J. Ivan Williams

Determining the need for hip and knee arthroplasty: the role of clinical severity and patients' preferences.

Background.Area variation in the use of surgical interventions such as arthroplasty is viewed as concerning and inappropriate. Objectives.To determine whether area arthroplasty rates reflect patient-related demand factors, we estimated the need for and the willingness to undergo arthroplasty in a high- and a low-use area of Ontario, Canada. Research Design. Population-based mail and telephone survey. Subjects.All adults aged ≥55 years in a high (n = 21,925) and low (n = 26,293) arthroplasty use area. Measures.We determined arthritis severity and comorbidity with questionnaires, established the presence of arthritis with examination and radiographs, and evaluated willingness to have arthroplasty with interviews. Potential arthroplasty need was defined as severe arthritis, no absolute contraindication for surgery, and evidence of arthritis on examination and radiographs. Estimates of need were then adjusted for patients’ willingness to undergo arthroplasty. Results.Response rates were 72.0% for questionnaires and interviews. The potential need for arthroplasty was 36.3/1,000 respondents in the high-rate area compared with 28.5/1,000 in the low-rate area (P <0.0001). Among individuals with potential need, only 14.9% in the high-rate area and 8.5% in the low-rate area were definitely willing to undergo arthroplasty (P = 0.03), yielding adjusted estimates of need of 5.4/1,000 and 2.4/1,000 in the high- and low-rate areas, respectively. Conclusions.Demonstrable need and willingness were greater in the high-rate area, suggesting these factors explain in part the observed geographic rate variations for this procedure. Among those with severe arthritis, no more than 15% were definitely willing to undergo arthroplasty, emphasizing the importance of considering both patients’ preferences and surgical indications when evaluating need and appropriateness of rates for surgery.

The role of children in reporting their physical disability

OBJECTIVE To explore the contributions of children during the development of a disability scale, and their competence using the new scale. DESIGN A new self-report measure of pediatric physical performance, the Activities Scale for Kids (ASK), was developed based on interviews and pilot testing with children. The ASK was then filled out by children on two occasions 2 weeks apart to assess the reliability of child self-report. Validity was assessed by comparison of interview data and ASK scores from children with similar data collected from their parents, and to clinician and family global ratings of disability. SETTING The study was conducted at a pediatric tertiary care hospital and its affiliated rehabilitation center. PATIENTS All subjects, 5 to 15 years of age, experienced activity limitations because of musculoskeletal disorders and were free of cognitive impairment. Thirty children (mean age, 11.5 years) participated in the development of the ASK, and 28 children (mean age, 11.4 years) participated in testing of reliability and validity. RESULTS Children generated items similar to those generated by parents (85% agreement) and identified 10 items not obtained from parents or the literature. Children demonstrated excellent test-retest reliability (intraclass correlation coefficient [ICC] = .97) using the ASK, and their scores were highly concordant with parent-reported ASK scores (ICC = .96). Validity was ascertained by comparison of ASK scores across different levels of disability based on global ratings of families and clinicians (p = .0023). CONCLUSION Children are able to play an important role in pediatric physical disability evaluation.

Gender and outpatient mental health service use

The purpose of this study is to describe gender differences in the use of outpatient mental health services and to identify potential determinants of this use. The study sample, N = 7475 respondents 18-64 years, was drawn from the Mental Health Supplement to the Ontario Health Survey. For theoretical and empirical reasons, type of mental disorder was defined as: a Mood and/or Anxiety Disorder (Mood/Anx) or a Substance Use Disorder and/or Antisocial Behaviours (Subs/Asb) within the past year. Use was defined in relation to providers seen within the past year. Descriptive and multiple logistic regression analyses were employed including type of mental disorder, social and economic factors. Female gender remained positively associated with any use despite adjustments (adjusted OR: 1.7; 95% CI: 1.2: 2.4). The magnitude of this association was consistent across the levels of the study variables and various measures of use except volume of use where there were no gender differences. Mood/Anx appeared to mediate the gender-use relationship and was strongly associated with use (adjusted OR: 8.4; 95% CI: 5.9; 11.9). Subs/Asb was also related to use (adjusted OR: 2.6; 95% CI: 1.5; 4.3) but not to the same degree as Mood/Anx. Mood/Anx explained 60% of the crude Subs/Asb-use relationship. The evidence to suggest that Subs/Asb mediated the gender-use relationship was mixed. These findings raise questions about gender differences in illness and reporting behaviours and the health care system in its preferential treatment of women and those with Mood/Anx.

Determinants of primary medical practice in adult cancer prevention.

The authors conducted a study of primary care physicians in the province of Quebec to ascertain their patterns of preventive practice with respect to cancer in four anatomic sites: breast, cervix, colon-rectum, and lung. They further explored the data set to elicit the determinants of the patterns of preventive practice. Scales were constructed encompassing practice behaviors for each type of cancer, continuing education intensity, knowledge, and belief. The content of these scales was delineated through factor analysis and their reliability assessed using Cronbachs alpha. Other variables were also considered in the conceptual model. Bivariate analysis and multivariate techniques were used. The models tested contained many significant interaction terms. A limited number of the first-order interactions was explored for each of the dependent variables. Different patterns emerged for each cancer type. Mode of reimbursement, continuing education, gender of physician, provider-related barriers to prevention, and knowledge were found to be the major predictors of prevention scores for the cancers studied, but their relative importance varied according to each cancer. The importance of better understanding the determinants of physician behaviors is emphasized and the existence of several possible explanatory models suggested.

An integrative framework for health-related research.

Research on the manifold aspects of health and health-care delivery, economics and administration has expanded rapidly in recent years and now engages a number of disciplines. The array of theories, methods, and analytical strategies derived from such diverse sources frequently impedes effective communication between investigators and sometimes renders it impossible. We propose a conceptual framework that encompasses all health-related research and demonstrates the relationships and interfaces between the various disciplines involved. The framework emerges from a classification of health-related research into studies of health states or health interventions followed by consideration of the level of analysis (e.g. cell, individual, community) employed and the purpose of each study (development, description, explanation, or evaluation).

Is there an association between lipid-lowering drugs and cholecystectomy?

Several studies have shown that fibrates can raise the biliary cholesterol saturation index (1–3), which is critical for gallstone formation (4). The Coronary Drug Project, which studied men with prior myocardial infarction, found that treatment with clofibrate increased the risk of cholecystectomy and gastrointestinal complications (5). A cross-sectional survey of the prevalence of gallstone disease in Spain found that fibrate use was the strongest independent risk factor for gallstones, albeit without delineating the effect of specific fibrate drugs (6). Other studies have implied that newer fibrate drugs, such as bezafibrate, fenofibrate, and gemfibrozil, may be less lithogenic than clofibrate (7–10). The Helsinki Heart Study did not find a statistically significant association between gemfibrozil use and cholecystectomy among dyslipidemic, middle-aged men, although the incidence was higher in the gemfibrozil group compared with the placebo group (11,12). Conversely, some (13,14), but not all (15), studies have suggested that statins reduce biliary cholesterol saturation and could protect against gallstones. In this study, we used population-based health-care databases to investigate the association between fibrate use and cholecystectomy compared with statins and a cardiovascular drug control group in older patients. METHODS