Marymount University

Abstract Gmsh is an open‐source 3‐D finite element grid generator with a build‐in CAD engine and post‐processor. Its design goal is to provide a fast, light and user‐friendly meshing tool with parametric input and advanced visualization capabilities. This paper presents the overall philosophy, the main design choices and some of the original algorithms implemented in Gmsh. Copyright © 2009 John Wiley & Sons, Ltd.

Scale developers often provide evidence of content validity by computing a content validity index (CVI), using ratings of item relevance by content experts. We analyzed how nurse researchers have defined and calculated the CVI, and found considerable consistency for item-level CVIs (I-CVIs). However, there are two alternative, but unacknowledged, methods of computing the scale-level index (S-CVI). One method requires universal agreement among experts, but a less conservative method averages the item-level CVIs. Using backward inference with a purposive sample of scale development studies, we found that both methods are being used by nurse researchers, although it was not always possible to infer the calculation method. The two approaches can lead to different values, making it risky to draw conclusions about content validity. Scale developers should indicate which method was used to provide readers with interpretable content validity information.

Nurse researchers typically provide evidence of content validity for instruments by computing a content validity index (CVI), based on experts' ratings of item relevance. We compared the CVI to alternative indexes and concluded that the widely-used CVI has advantages with regard to ease of computation, understandability, focus on agreement of relevance rather than agreement per se, focus on consensus rather than consistency, and provision of both item and scale information. One weakness is its failure to adjust for chance agreement. We solved this by translating item-level CVIs (I-CVIs) into values of a modified kappa statistic. Our translation suggests that items with an I-CVI of .78 or higher for three or more experts could be considered evidence of good content validity.

This article examines the developmental process of cooperative interorganizational relationships (IORs) that entail transaction-specific investments in deals that cannot be fully specified or controlled by the parties in advance of their execution. A process framework is introduced that focuses on formal, legal, and informal social-psychological processes by which organizational parties jointly negotiate, commit to. and execute their relationship in ways that achieve efficient and equitable outcomes and internal solutions to conflicts when they arise. The framework is elaborated with a set of propositions that explain how and why cooperative IORs emerge, evolve, and dissolve. The propositions have academic implications for enriching interorganizational relationships, transaction cost economics, agency theories, and practical implications for managing the relationship journey.

Partial table of contents: Reliability Concepts and Reliability Data. Nonparametric Estimation. Other Parametric Distributions. Probability Plotting. Bootstrap Confidence Intervals. Planning Life Tests. Degradation Data, Models, and Data Analysis. Introduction to the Use of Bayesian Methods for Reliability Data. Failure--Time Regression Analysis. Accelerated Test Models. Accelerated Life Tests. Case Studies and Further Applications. Epilogue. Appendices. References. Indexes.

We have developed a 12-item questionnaire for patients having a total knee replacement (TKR). We made a prospective study of 117 patients before operation and at follow-up six months later, asking them to complete the new questionnaire and the form SF36. Some also filled in the Stanford Health Assessment Questionnaire (HAQ). An orthopaedic surgeon completed the American Knee Society (AKS) clinical score. The single score derived from the new questionnaire had high internal consistency, and its reproducibility, examined by test-retest reliability, was found to be satisfactory. Its validity was established by obtaining significant correlations in the expected direction with the AKS scores and the relevant parts of the SF36 and HAQ. Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at follow-up. We also compared change in scores with the patients' retrospective judgement of change in their condition. The effect size for the new questionnaire compared favourably with those for the relevant parts of the SF36. The change scores for the new knee questionnaire were significantly greater (p < 0.0001) for patients who reported the most improvement in their condition. The new questionnaire provides a measure of outcome for TKR that is short, practical, reliable, valid and sensitive to clinically important changes over time.

It is important that the medical profession play a significant role in critically evaluating the use of diagnostic procedures and therapies as they are introduced and tested in the detection, management, or prevention of disease states. Rigorous and expert analysis of the available data documenting relative benefits and risks of those procedures and therapies can produce helpful guidelines that improve the effectiveness of care, optimize patient outcomes, and favorably affect the overall cost of care by focusing resources on the most effective strategies.

Background: Estimating the burden of disease attributable to long-term exposure to fine particulate matter (PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk (RR) function. However, adequate direct evidence to identify the shape of the mortality RR functions at the high ambient concentrations observed in many places in the world is lacking.Objective: We developed RR functions over the entire global exposure range for causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). We also developed RR functions for the incidence of acute lower respiratory infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children &lt; 5 years of age.Methods: We fit an integrated exposure–response (IER) model by integrating available RR information from studies of ambient air pollution (AAP), second hand tobacco smoke, household solid cooking fuel, and active smoking (AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass. We derived population attributable fractions (PAFs) for every country based on estimated worldwide ambient PM2.5 concentrations.Results: The IER model was a superior predictor of RR compared with seven other forms previously used in burden assessments. The percent PAF attributable to AAP exposure varied among countries from 2 to 41 for IHD, 1 to 43 for stroke, &lt; 1 to 21 for COPD, &lt; 1 to 25 for LC, and &lt; 1 to 38 for ALRI.Conclusions: We developed a fine particulate mass–based RR model that covered the global range of exposure by integrating RR information from different combustion types that generate emissions of particulate matter. The model can be updated as new RR information becomes available.Citation: Burnett RT, Pope CA III, Ezzati M, Olives C, Lim SS, Mehta S, Shin HH, Singh G, Hubbell B, Brauer M, Anderson HR, Smith KR, Balmes JR, Bruce NG, Kan H, Laden F, Prüss-Ustün A, Turner MC, Gapstur SM, Diver WR, Cohen A. 2014. An integrated risk function for estimating the global burden of disease attributable to ambient fine particulate matter exposure. Environ Health Perspect 122:397–403; http://dx.doi.org/10.1289/ehp.1307049

Five subscales were derived from the Nursing Work Index (NWI) to measure the hospital nursing practice environment, using 1985-1986 nurse data from 16 magnet hospitals. The NWI comprises organizational characteristics of the original magnet hospitals. The psychometric properties of the subscales and a composite measure were established. All measures were highly reliable at the nurse and hospital levels. Construct validity was supported by higher scores of nurses in magnet versus nonmagnet hospitals. Confirmatory analyses of contemporary data from 11,636 Pennsylvania nurses supported the subscales. The soundness of the new measures is supported by their theoretical and empirical foundations, conceptual integrity, psychometric strength, and generalizability. The measures could be used to study how the practice environment influences nurse and patient outcomes.

To investigate the prevalence of osteoarthritis (OA) of the knee in elderly subjects, we studied the Framingham Heart Study cohort, a population-based group. During the eighteenth biennial examination, we evaluated the cohort members for OA of the knee by use of medical history, physical examination, and anteroposterior (standing) radiograph of the knees. Radiographs were obtained on 1,424 of the 1,805 subjects (79%). Their ages ranged from 63-94 years (mean 73). Radiographs were read by a radiologist who specializes in bone and joint radiology, and were graded 0-4 according to the scale described by Kellgren and Lawrence. OA was defined as grade 2 changes (definite osteophytes), or higher, in either knee. Radiographic evidence of OA increased with age, from 27% in subjects younger than age 70, to 44% in subjects age 80 or older. There was a slightly higher prevalence of radiographic changes of OA in women than in men (34% versus 31%); however, there was a significantly higher proportion of women with symptomatic disease (11% of all women versus 7% of all men; P = 0.003). The age-associated increase in OA was almost entirely the result of the marked age-associated increase in the incidence of OA in the women studied. This study extends current knowledge about OA of the knee to include elderly subjects, and shows that the prevalence of knee OA increases with age throughout the elderly years.

An instrument to measure the stigma perceived by people with HIV was developed based on the literature on stigma and psychosocial aspects of having HIV. Items surviving two rounds of content review were assembled in a booklet and distributed through HIV-related organizations across the United States. Psychometric analysis was performed on 318 questionnaires returned by people with HIV (19% women, 21% African American, 8% Hispanic). Four factors emerged from exploratory factor analysis: personalized stigma, disclosure concerns, negative self-image, and concern with public attitudes toward people with HIV. Extraction of one higher-order factor provided evidence of a single overall construct. Construct validity also was supported by relationships with related constructs: self-esteem, depression, social support, and social conflict. Coefficient alphas between .90 and .93 for the subscales and .96 for the 40-item instrument provided evidence of internal consistency reliability. The HIV Stigma Scale was reliable and valid with a large, diverse sample of people with HIV.

BACKGROUND: The Cochrane Collaboration is strongly encouraging the use of a newly developed tool, the Cochrane Collaboration Risk of Bias Tool (CCRBT), for all review groups. However, the psychometric properties of this tool to date have yet to be described. Thus, the objective of this study was to add information about psychometric properties of the CCRBT including inter-rater reliability and concurrent validity, in comparison with the Effective Public Health Practice Project Quality Assessment Tool (EPHPP). METHODS: Both tools were used to assess the methodological quality of 20 randomized controlled trials included in our systematic review of the effectiveness of knowledge translation interventions to improve the management of cancer pain. Each study assessment was completed independently by two reviewers using each tool. We analysed the inter-rater reliability of each tool's individual domains, as well as final grade assigned to each study. RESULTS: The EPHPP had fair inter-rater agreement for individual domains and excellent agreement for the final grade. In contrast, the CCRBT had slight inter-rater agreement for individual domains and fair inter-rater agreement for final grade. Of interest, no agreement between the two tools was evident in their final grade assigned to each study. Although both tools were developed to assess 'quality of the evidence', they appear to measure different constructs. CONCLUSIONS: Both tools performed quite differently when evaluating the risk of bias or methodological quality of studies in knowledge translation interventions for cancer pain. The newly introduced CCRBT assigned these studies a higher risk of bias. Its psychometric properties need to be more thoroughly validated, in a range of research fields, to understand fully how to interpret results from its application.

BACKGROUND: The authors designed a prospective longitudinal study to investigate the hypothesis that advancing age is a risk factor for postoperative cognitive dysfunction (POCD) after major noncardiac surgery and the impact of POCD on mortality in the first year after surgery. METHODS: One thousand sixty-four patients aged 18 yr or older completed neuropsychological tests before surgery, at hospital discharge, and 3 months after surgery. Patients were categorized as young (18-39 yr), middle-aged (40-59 yr), or elderly (60 yr or older). At 1 yr after surgery, patients were contacted to determine their survival status. RESULTS: At hospital discharge, POCD was present in 117 (36.6%) young, 112 (30.4%) middle-aged, and 138 (41.4%) elderly patients. There was a significant difference between all age groups and the age-matched control subjects (P < 0.001). At 3 months after surgery, POCD was present in 16 (5.7%) young, 19 (5.6%) middle-aged, and 39 (12.7%) elderly patients. At this time point, the prevalence of cognitive dysfunction was similar between age-matched controls and young and middle-aged patients but significantly higher in elderly patients compared to elderly control subjects (P < 0.001). The independent risk factors for POCD at 3 months after surgery were increasing age, lower educational level, a history of previous cerebral vascular accident with no residual impairment, and POCD at hospital discharge. Patients with POCD at hospital discharge were more likely to die in the first 3 months after surgery (P = 0.02). Likewise, patients who had POCD at both hospital discharge and 3 months after surgery were more likely to die in the first year after surgery (P = 0.02). CONCLUSIONS: Cognitive dysfunction is common in adult patients of all ages at hospital discharge after major noncardiac surgery, but only the elderly (aged 60 yr or older) are at significant risk for long-term cognitive problems. Patients with POCD are at an increased risk of death in the first year after surgery.

BACKGROUND: Intraoperative hypotension may contribute to postoperative acute kidney injury (AKI) and myocardial injury, but what blood pressures are unsafe is unclear. The authors evaluated the association between the intraoperative mean arterial pressure (MAP) and the risk of AKI and myocardial injury. METHODS: The authors obtained perioperative data for 33,330 noncardiac surgeries at the Cleveland Clinic, Ohio. The authors evaluated the association between intraoperative MAP from less than 55 to 75 mmHg and postoperative AKI and myocardial injury to determine the threshold of MAP where risk is increased. The authors then evaluated the association between the duration below this threshold and their outcomes adjusting for potential confounding variables. RESULTS: AKI and myocardial injury developed in 2,478 (7.4%) and 770 (2.3%) surgeries, respectively. The MAP threshold where the risk for both outcomes increased was less than 55 mmHg. Compared with never developing a MAP less than 55 mmHg, those with a MAP less than 55 mmHg for 1-5, 6-10, 11-20, and more than 20 min had graded increases in their risk of the two outcomes (AKI: 1.18 [95% CI, 1.06-1.31], 1.19 [1.03-1.39], 1.32 [1.11-1.56], and 1.51 [1.24-1.84], respectively; myocardial injury 1.30 [1.06-1.5], 1.47 [1.13-1.93], 1.79 [1.33-2.39], and 1.82 [1.31-2.55], respectively]. CONCLUSIONS: Even short durations of an intraoperative MAP less than 55 mmHg are associated with AKI and myocardial injury. Randomized trials are required to determine whether outcomes improve with interventions that maintain an intraoperative MAP of at least 55 mmHg.

Assistant Professor Department of Physical Therapy University of the Sciences in Philadelphia Philadelphia, PA

STUDY DESIGN: A new surgical strategy for treatment of patients with spinal metastases was designed, and 61 patients were treated based on this strategy. OBJECTIVES: To propose a new surgical strategy for the treatment of patients with spinal metastases. SUMMARY OF BACKGROUND DATA: A preoperative score composed of six parameters has been proposed by Tokuhashi et al for the prognostic assessment of patients with metastases to the spine. Their scoring system was designed for deciding between excisional or palliative procedures. Recently, aggressive surgery, such as total en bloc spondylectomy for spinal metastases, has been advocated for selected patients. Surgical strategies should include various treatments ranging from wide or marginal excision to palliative treatment with hospice care. METHODS: Sixty-seven patients with spinal metastases who had been treated from 1987-1991 were reviewed, and prognostic factors were evaluated retrospectively (phase 1). A new scoring system for spinal metastases that was designed based on these data consists of three prognostic factors: 1) grade of malignancy (slow growth, 1 point; moderate growth, 2 points; rapid growth, 4 points), 2) visceral metastases (no metastasis, 0 points; treatable, 2 points: untreatable, 4 points), and 3) bone metastases (solitary or isolated, 1 point; multiple, 2 points). These three factors were added together to give a prognostic score between 2-10. The treatment goal for each patient was set according to this prognostic score. The strategy for each patient was decided along with the treatment goal: a prognostic score of 2-3 points suggested a wide or marginal excision for long-term local control; 4-5 points indicated marginal or intralesional excision for middle-term local control; 6-7 points justified palliative surgery for short-term palliation; and 8-10 points indicated nonoperative supportive care. Sixty-one patients were treated prospectively according to this surgical strategy between 1993-1996 (phase 2). The extent of the spinal metastases was stratified using the surgical classification of spinal tumors, and technically appropriate and feasible surgery was performed, such as en bloc spondylectomy, piecemeal thorough excision, curettage, or palliative surgery. RESULTS: The mean survival time of the 28 patients treated with wide or marginal excision was 38.2 months (26 had successful local control). The mean survival time of the 13 patients treated with intralesional excision was 21.5 months (nine had successful local control). The mean survival time of the 11 patients treated with palliative surgery and stabilization was 10.1 months (eight had successful local control). The mean survival time of the patients with terminal care was 5.3 months. CONCLUSIONS: A new surgical strategy for spinal metastases based on the prognostic scoring system is proposed. This strategy provides appropriate guidelines for treatment in all patients with spinal metastases.

Administrator; Agency for Health Care Policy and Research; Rockville, MD Deadlines for letters of intent and applications vary. Information on and copies of those RFAs and AHCPR's Program Announcement are available from AHCPR's web site or from AHCPR's contractor: Equals Three Communications, Inc., 7910 Woodmont Avenue, Suite 200, Bethesda, MD, 20814-3015. Telephone: (301) 656-3100 or Telecopier: (301) 652-5264.

EXPOSURE to alcohol and some anesthetic and sedative drugs cause histopathologic changes in the developing brains of animals.1–3Implicated drugs include N -methyl-d-aspartate glutamate receptor antagonists (e.g. , ketamine, nitrous oxide) and agents with γ-aminobutyric acid A mimetic properties (e.g. , pentobarbital, diazepam, isoflurane, halothane, propofol). Some studies suggest that even relatively brief single exposures trigger changes, especially when combinations of agents are used.1–6In one report, histologic neurodegeneration was associated with a diminished capacity to retain learned behaviors.7It is not known whether findings in rodent models can be extrapolated to humans, but emerging histologic data in nonhuman primates8tend to confirm findings in rodents. These findings have engendered considerable concern among the U.S. Food and Drug Administration and others.5Except for case series reporting developmental outcomes of critically ill neonates and children undergoing repair of congenital heart disease,9–12which have multiple limitations, there are no data that can yield insight into whether exposure to anesthesia and surgery during human development causes clinically relevant impairment in neural development.One challenge to determining whether exposure to anesthesia and surgery in early life impairs neural development is defining relevant outcomes. Learning disabilities (LD) may be an appropriate outcome measure. Children with LD experience problems with one or more of the basic psychological processes involved in understanding or in using spoken or written language, which may manifest itself in an imperfect ability to listen, think, speak, read, write, spell, or perform mathematical calculations. Because learning disabilities are routinely sought on the basis of standardized individualized testing in educational settings and because of the relatively high incidence rate of LD,13this outcome is available in large populations of children.The purpose of the current study was to determine whether there was an association between exposure to anesthesia during the first 4 yr of life and the development of any learning disability in a birth cohort of children in Olmsted County, Minnesota.The Mayo Clinic and Olmsted Medical Center Institutional Review Boards (both in Rochester, Minnesota) approved this study. A birth cohort of children born in Rochester, Minnesota, identified in previous work by the authors13–16formed the basis of the current study. All children (n = 8,548) born between January 1, 1976, and December 31, 1982, to mothers residing at the time of delivery in the five Olmsted County, Minnesota, townships (comprising Minnesota Independent School District No. 535, the Rochester public and private school system) were identified through computerized birth certificate information obtained from the Minnesota Department of Health, Division of Vital Statistics. To ascertain vital status (still living in Rochester, moved, or deceased), for each member of the birth cohort during the 1995–1996 school year, resources available from the Rochester Epidemiology Project,17Minnesota Independent School District No. 535, the Reading Center/Dyslexia Institute of Minnesota, and the Minnesota Department of Health were used. Children who left Olmstead County before age 5 yr (i.e. , moved or died; n = 2,830) were not included in the final study cohort.14Through the Rochester Epidemiology Project, all diagnoses and surgical procedures recorded at all Rochester medical facilities are indexed for automated retrieval. This diagnostic index expedites retrieval of the unit (or dossier) medical record, which includes the history of all encounters in the hospital, community and ambulatory medical and social services, emergency department, outpatient clinics, and home visits as well as laboratory and psychological test results from birth until patients no longer reside in the community. The evaluation and instructional resources of Minnesota Independent School District No. 535, the school system for the city of Rochester, are of high quality, and the district has a long tradition of excellent care and management of children with all types of handicapping conditions, including LD. Through a contractual research agreement, all public (19 primary, 3 junior high, 3 high schools) and nonpublic (12 primary, 10 junior high, 4 high schools) schools gave permission to access their richly documented cumulative educational records for every child from this birth cohort. Under a second research agreement, permission was obtained to access the resources of the privately owned Reading Center/Dyslexia Institute of Minnesota, the only private tutoring agency in the community during the years relevant to this study. The Reading Center/Dyslexia Institute of Minnesota files included a pool of some 3,000 evaluations and outcomes of tutorial instruction that spanned nearly 50 yr. All of these records, including the results of all individually administered intelligence quotient (IQ; primarily age-appropriate Wechsler scales) and achievement (primarily Woodcock–Johnson tests) tests and medical, educational, and socioeconomic information were abstracted by trained personnel, using detailed data abstraction protocols.Learning disabilities (including reading, written language, and math disabilities) were diagnosed using research criteria based on three formulas. In each of the following formulas, X is equal to the study subject's IQ score, and Y represents the predicted standard score from the achievement test. The regression formula–Minnesota, Y < 17.40 + 0.62X, is issued by the Minnesota Department of Education.18Children classified as having LD by this formula had standard scores in academic achievement that were more than 1.75 SDs below their predicted standard score from an individually administered measure of cognitive ability (IQ). The value 0.62 represents the correlation between IQ and achievement used in the formula from the state of Minnesota. The discrepancy nonregression method was used in Minnesota Independent School District No. 535 before 1989 and included the school years of the children in our birth cohort. By using this approach, differences between standard scores on measures of intelligence and aptitude and measures of test achievement that were believed to be important varied by grade as follows: (1) kindergarten through 3rd grade, 15 or more standard score points difference, with achievement lower; (2) 4th through 6th grade, 19 or more points difference, achievement lower; and (3) 7th through 12th grade, 23 or more points difference. Finally, the low-achievement method (X ≥ 80 [aptitude] and Y ≤ 90 [achievement]) represents a recent concept in identifying LD independent of measured cognitive ability, assuming that cognitive ability is at least in the low average range.19Children meeting the criteria before age 19 yr for at least one of the three LDs (reading, written language, and math disabilities) using IQ and achievement scores obtained within the same calendar year were identified as LD cases regardless of presence or absence of any comorbid conditions.13We identified all members of the birth cohort who underwent any type of surgery or diagnostic procedure necessitating general anesthesia before their fourth birthday, using the Mayo Clinic Surgical Information Retrieval System and a similar resource for procedures performed at Olmsted County Medical Center. The choice of age range was based on the analogous developmental stage of animal models in which anesthetic effects on neurodevelopment have been shown.1,20Procedures such as neonatal circumcision performed without anesthesia were excluded from review.For the children undergoing anesthesia, the following information was abstracted: American Society of Anesthesiologists physical status (ASA PS) classification, type of surgery or procedure and urgency, total duration of anesthesia, number of anesthetic exposures, age(s) at which exposure occurred, anesthetic agents (inhalational, intravenous, sedatives), and comorbidities (including syndromes that can be associated with mental retardation, congenital heart disease, and neurologic diseases). For all children in the cohort (including those who did not receive anesthesia), sex, gestational age at birth, birth weight, Apgar scores at 1 and 5 min (Apgar scores were available for children born 1980–1982), complications of pregnancy, complications of labor and delivery, number of births (multiple or single), need for induced labor, and the mother's and father's age and level of education (< 12 yr, 12 yr, > 12 yr) were available from birth certificates.The primary outcome for the current analysis was LD based on individually administered IQ and academic achievement test scores using any of the three standard formulas for determining the presence of reading written language or math LD. The primary risk factor of interest for this investigation was exposure to general anesthesia before age 4 yr. Preliminary analyses were performed to compare demographic, pregnancy and delivery, and parental characteristics between those who were exposed versus unexposed to general anesthesia before age 4 yr using the two-sample t test (or rank sum test) for continuous variables and the chi-square test (or Fisher exact test) for categorical variables.Individuals were followed up from birth until the date they first met the LD criteria using any of the three standard formulas for determining the presence of reading, written language, and math LD. Cumulative incidence rates of LD were calculated according to the method of Kaplan and Meier with data censored at the initial occurrence of emigration, death, last follow-up date, or age 19 yr. Proportional hazards regression was used to assess whether anesthetic exposure was a risk factor for LD. For these analyses, anesthetic exposure was quantified as any exposure to general anesthesia before age 4 yr (yes vs. no), the number of exposures to general anesthesia before age 4 yr (none, one, two, three or more), and the cumulative duration of exposure (treated as a continuous variable and also categorically using 30-min intervals). Both unadjusted and adjusted analyses were performed. In all cases, separate models were used to evaluate the different anesthesia exposure variables. The covariates that were included in the adjusted analyses include gestational age, sex, and birth weight. In the adjusted analysis, only those individuals for whom complete covariate information was available were included. Results were summarized using hazard ratio estimates and corresponding 95% confidence intervals (CIs). In all cases, two-tailed P values less than 0.05 were considered to be statistically significant. Analyses were performed using SAS statistical software (version 9.1; SAS Institute, Inc., Cary, NC).Between 1976 and 1982, there were 8,548 children born in the five Olmsted County, Minnesota, townships comprising Minnesota Independent School District No. 535, and 5,718 of these children still resided in the community at age 5 yr. Of these, 19 individuals were diagnosed with severe mental retardation and were excluded, as were 342 patients who denied research authorization for the use of their medical records. Therefore, 5,357 children are included in the current report. Of those, 593 underwent procedures requiring general anesthesia before age 4 yr. In comparison to unexposed children, those exposed to anesthesia before age 4 yr had lower birth weight (P < 0.001), lower gestational age (P = 0.001), and were more likely to be male (P < 0.001) (table 1and Supplemental Digital Content 1 [see table, which illustrates birth, maternal, and paternal characteristics, https://links.lww.com/A825]). All of these factors were subsequently used as adjustors in multivariate analysis. Children exposed to anesthesia also had mothers with higher levels of maternal education (P = 0.039); however, this factor was not included as an adjustor in subsequent analysis because these data were missing for approximately 10% of children. Apgar scores were not different between two groups for those in whom data were available. The peripartum complications of those exposed or not exposed to anesthesia were similar (table 2and Supplemental Digital Content 2 [see table, which illustrates peripartum complications from birth certificates, https://links.lww.com/A826]), with the exception that the mothers of those exposed to anesthesia experienced a slightly higher rate of peripartum hemorrhage and prolonged labor.The 593 children exposed to anesthesia underwent 875 procedures, with 449 (75.7%) having a single procedure (table 3). Of the children exposed to anesthesia, 438 (74%) were classified as ASA PS I (table 3). Types of surgeries are shown in table 4. Most anesthetics included halothane (88%) and nitrous oxide (91%); 9% included ketamine (table 5).A total of 932 children developed an LD before age 19 yr as assessed by individually administered IQ and achievement tests scored using any of the three standard formulas (estimated cumulative incidence 20.5%; 95% CI, 19.3–21.7%). For both unadjusted and adjusted (for sex, birth weight, and gestational age) analyses, the risk for the development of LD (compared with children not exposed to anesthesia) increased (P < 0.001) with the number of exposures to anesthesia before age 4 yr (table 6). The risk was not increased for the 449 children exposed to a single anesthetic (adjusted hazard ratio = 1.00; 95% CI, 0.79–1.27; table 6). However, the risk was significantly increased for children exposed to two or more anesthetics (table 6and fig. 1). The estimated incidence of LD by age 19 yr was 20.0% (95% CI, 18.8–21.3%) in those with no exposure to anesthesia, 20.4% (95% CI, 16.3–24.3%) in those with single exposure, and 35.1% (95% CI, 26.2–42.9%) in those with multiple exposures. The risk for LD was also increased with longer cumulative duration of anesthesia (P = 0.016 and P = 0.027 from adjusted analysis assessing cumulative duration of anesthesia as a continuous and as a categorical variable, respectively; table 6).Children with multiple exposures to anesthesia were also more likely to be assigned a higher ASA PS compared with those with a single exposure, indicative of more severe comorbidity in the judgment of the anesthesia provider (fig. 2). However, when the analyses assessing the relation between number of exposures and cumulative duration of exposures with development of LD were repeated after eliminating surgical patients with ASA PS of III or greater, the findings were similar: anesthesia was a significant risk factor for the development of LD in children receiving multiple, but not single, anesthetics (data not shown). Detailed information regarding each of the 144 children who received multiple anesthetic exposures before age 4 yr, including their medical diagnoses before and after age 4 yr, are provided in Supplemental Digital Content 3 (see table, which illustrates diagnoses from the medical record in the 144 children who received multiple anesthetics before age 4 yr, https://links.lww.com/A827).In this population-based birth cohort, exposure to anesthesia before age 4 yr was a risk factor for the development of LD in children receiving multiple, but not single, anesthetics. The cumulative incidence of LD diagnosed by age 19 yr among those with repeated anesthetic exposures was almost twice as high (35.1%) compared with children not exposed to anesthesia (20.0%).Late prenatal and early postnatal neural development is vulnerable to pharmacologic and environmental influences.20–22Exposure of immature animals to compounds with γ-aminobutyric acid mimetic receptor agonist or N -methyl-d-aspartate receptor antagonist properties induces apoptotic degeneration of neurons in various brain regions.1–4,7,23In particular, drugs with sedative and anesthetic properties (including isoflurane, nitrous ketamine, halothane, and neurodegeneration when administered at and of some animal these histologic changes have been associated with learning and assessed by and these data have and research on the of the Food and Drug Administration and is not known whether exposure to anesthetics or in A recent neurologic after surgery and anesthesia in children. Some studies of developmental outcomes in patients undergoing repair for congenital heart suggest neurologic studies outcomes of neonates with and or the of these was not to the effects of characteristics, and surgery from the effects of anesthesia, and the for is a birth cohort to study the incidence of learning disabilities in a cohort provided All of these children resided in the same any of public private and received care at one of two facilities Clinic and Olmsted County Medical to all available medical and educational records. These records, with of to perform a of a clinically significant outcome that the learning in an animal complete data available from birth records to for factors known to the of LD gestational age, and birth anesthesia records were available for all procedures, and anesthetic was The of surgical procedures the population-based of the cohort, is not patients undergoing more procedures, as is the case with studies at academic exposure to anesthesia significantly there be a relation between exposure and a relevant for such a relation between anesthetic exposure and LD in two risk was increased for children requiring multiple exposure (adjusted hazard ratio of for two exposures and for three or more table but not for single exposures to anesthesia (adjusted hazard ratio of risk was increased for longer of anesthesia, statistical for cumulative duration of min or (table 6). anesthesia exposure was as a variable exposure before age 4 exposure was a significant risk factor for LD in unadjusted ratio of but not adjusted ratio of analysis. The likely the that the of children received only one exposure, which was not associated with increased study has between effects of anesthesia itself and factors associated with anesthesia, such as the to surgical children requiring anesthesia may in important from those who and such differences may risk for LD. Therefore, that requiring multiple anesthetics is a for that LD risk and that exposure to anesthetic drugs is not adjusted for known factors (for which data were to LD risk that between the groups with the exception of maternal because data were missing in a significant number of children. However, when analysis was repeated children with missing data and including maternal education as a the results were the same (data not shown). Children requiring repeated procedures may have a higher of which may risk for LD. For and children requiring repair of congenital heart may more children requiring multiple procedures were by their to have more severe disease, as by higher ASA did not the medical records of the children not requiring anesthesia, not use medical diagnoses as covariates in the ASA PS is not available in these children. However, among the 144 children receiving multiple LD was not more in children with higher ASA and among all children receiving anesthesia, LD did not with ASA PS in analysis (data not shown). the association of LD with repeated anesthetic exposure was still when the analysis was repeated after eliminating surgical patients with ASA PS of III or These findings suggest that ASA PS was not associated with LD risk in our cohort, and that the increased of LD in children receiving multiple anesthetics be primarily to those children with multiple medical of anesthetic is an but of the of anesthetics than nitrous cause of children received ketamine to perform a separate analysis for this animal there is a time of to the effects of anesthetic exposure (e.g. , approximately after birth in to to a of the to study the effects of anesthetic exposure may be In humans, the of has been considered to through age 3 was the basis for our choice of the fourth as the age to anesthetic However, the between of human and animal neurodevelopment is and suggest that the corresponding to the time of risk in animal models (e.g. , approximately before birth until 2 after birth in is in of and first after repeated our analysis anesthetic exposure before age 2 yr than age 4 yr) on the risk of LD and similar results (see Supplemental Digital Content which illustrates the cumulative of learning disabilities by the age at exposure, and table, Supplemental Digital Content which illustrates the effects of anesthetic exposure before age 2 yr on risk for developing learning did not have of cases to a more age range (e.g. , is to from the birth cohort of 8,548 children. cohort studies can be as a of from the community. For the and of care available in Rochester, children with a higher level of medical need may not to and be in the cohort. This to the surgical children with more severe However, a comparison of children who left the community before age 5 yr and those who after age 5 yr age of school that the children included in the study are of the birth to the of this cohort is that in these years Rochester was a which may the of these results to to be whether LD is a relevant outcome measure for any effects of anesthesia in humans, that and socioeconomic factors may also LD. on the animal studies an association between the neurodegeneration by exposure to anesthetics and learning that LD is a relevant in also to be whether the in the of LD among children with multiple anesthetic exposures is to one type of LD (i.e. , written language, and reading For of this analysis, a of LD to the number of children with LD and the ability to by type of LD be of but be by the between types (i.e. , some children have more than one type of and the need for increased of to of the in the current study. are a of outcomes that be but testing that is to in large population-based in this population-based birth cohort, exposure to anesthesia before age 4 yr was a significant risk factor for the development of LD in children receiving multiple, but not single, anesthetics. These data whether exposure to anesthesia itself may to the of LD or whether the need for anesthesia is a for factors that to LD. However, these results suggest that the of effects of repeated anesthetic exposures on human neurodevelopment be the Mayo Rochester, for in the Rochester Epidemiology Project, and of Mayo for and experience in the of learning The Mayo and members of the Learning for data Independent School District No. and the Reading Center/Dyslexia Institute of Minnesota for their and The also Mayo and in for in medical records from Olmsted County Medical Rochester, Minnesota.

Telephone interviews are largely neglected in the qualitative research literature and, when discussed, they are often depicted as a less attractive alternative to face-to-face interviewing. The absence of visual cues via telephone is thought to result in loss of contextual and nonverbal data and to compromise rapport, probing, and interpretation of responses. Yet, telephones may allow respondents to feel relaxed and able to disclose sensitive information, and evidence is lacking that they produce lower quality data. This apparent bias against telephone interviews contrasts with a growing interest in electronic qualitative interviews. Research is needed comparing these modalities, and examining their impact on data quality and their use for studying varying topics and populations. Such studies could contribute evidence-based guidelines for optimizing interview data.

In this paper the author proposes a new qualitative method for building conceptual frameworks for phenomena that are linked to multidisciplinary bodies of knowledge. First, he redefines the key terms of concept, conceptual framework, and conceptual framework analysis. Concept has some components that define it. A conceptual framework is defined as a network or a “plane” of linked concepts. Conceptual framework analysis offers a procedure of theorization for building conceptual frameworks based on grounded theory method. The advantages of conceptual framework analysis are its flexibility, its capacity for modification, and its emphasis on understanding instead of prediction.