Iatrogenic risk factors for cytomegalovirus retinitis.

BACKGROUND: To determine the iatrogenic risk factors for cytomegalovirus (CMV) retinitis in patients with the acquired immunodeficiency syndrome (AIDS). METHODS: The case-control study included 120 patients with CMV retinitis and 159 patients without CMV retinitis, all of whom had AIDS and CD4 counts less than 50 cells/microL at the time of diagnosis of retinitis or at the defined corresponding date in the controls. Iatrogenic risk factors studied were corticosteroid use, treatment with chemotherapy, treatment with radiotherapy, and blood transfusions. RESULTS: Among the risk factors studied, only steroid use was predictive of CMV retinitis (odds ratio 6.41, 95% confidence interval 2.35-17.51). Based on this study, the use of steroids systemically elevated the risk of CMV retinitis.

Surgery versus collagen for female stress urinary incontinence: economic assessment in Ontario and Quebec.

INTRODUCTION AND OBJECTIVE: The purpose of this study was to evaluate the cost-effectiveness of surgery versus collagen injection to treat female stress urinary incontinence after the failure of initial surgical treatment. The analysis was conducted from the health care system perspectives of Ontario and Quebec. MATERIALS AND METHODS: A decision-tree was constructed to compare each of three surgeries (i.e., retropubic suspension, transvaginal suspension, sling procedures) with collagen. An average cost estimate was generated for each intervention, as was an incremental cost-effectiveness ratio for each surgery-collagen comparison. RESULTS: In both Ontario and Quebec, the treatment with the lowest average cost was collagen (Ontario: collagen = 2695 dollars; Quebec: collagen = 2718 dollars). However, the surgeries had higher probabilities of success (defined as 'cure' - no urine leakage during follow-up examinations), with point estimates of at least.79 (.53 for collagen). Incremental cost-effectiveness ratios for the base case analyses of all treatment comparisons indicated that the cost to cure an additional patient with surgery could range from 1824 dollars to 6814 dollars in Ontario and 1388 dollars to 3008 dollars in Quebec. These ratios were sensitive to changes in the mean number of injections for collagen patients and to a reduction in the length of hospital stay for surgery to 1 day. CONCLUSIONS: Collagen injection may be cost-effective as a follow-up treatment to initial surgical failure in both Ontario and Quebec when the number of injections is kept to a minimum and hospital stays after surgery are relatively lengthy. Otherwise, surgery may be cost-effective.

Laboratory-based risk factors for cytomegalovirus retinitis.

BACKGROUND: Very few studies have investigated risk factors for cytomegalovirus (CMV) retinitis. Identifying these risk factors will have many benefits, including helping establish screening regimens, examination frequency regimens, and targeted prophylaxis with oral therapy with valganciclovir or other anti-CMV agents. The purpose of this study was to determine the laboratory-based risk factors for CMV retinitis in patients with AIDS. METHODS: We conducted a case-control study involving 120 patients in whom CMV retinitis had been diagnosed in 1990-99 and 159 patients without CMV retinitis from the same period. The sampling was from a primary study base in eastern Ontario and western Quebec of patients with AIDS and CD4 counts less than 50 cells/microL at the time of diagnosis of retinitis in the case subjects or an analogous date for the control subjects. There were two components to the study. In the first component (n = 279) we examined standard-of-care laboratory tests (hematologic and nutrition variables) done during the study period. In the second component (n = 57), which was a subset of the first, we examined laboratory tests (HLA type, qualitative and quantitative CMV polymerase chain reaction [PCR] and HIV load) on stored blood samples from the eastern Ontario site. Multivariate logistic regression was used to model the data and control for confounding. We developed a systematic model-building strategy, from assumption testing to model building to model checking. RESULTS: A low hemoglobin concentration was a statistically significant predictor of CMV retinitis (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.94-0.98). Both qualitative CMV PCR (OR 21.71, 95% CI 1.80-261.67) and quantitative CMV PCR (OR 33.03,95% CI 2.32-469.39) were strong predictors of CMV retinitis. Among the 80 HLA types tested, HLA-Bw4 (OR 11.68, 95% CI 1.29-105.82) and HLA-DRB115 (OR 9.34, 95% CI 1.14-76.41) were significant predictors of CMV retinitis, whereas HLA-Cw7 was protective against CMV retinitis (OR 0.09, 95% CI 0.01-0.67). INTERPRETATION: We have identified laboratory variables that elevate (or decrease) the risk of CMV retinitis. These findings may be useful to clinicians and health policy experts in developing rational guidelines for screening, examination frequency and targeted prophylaxis for patients with AIDS.

Effectiveness of WBC reduction in neonates: what is the evidence of benefit?

BACKGROUND: The presence of WBCs in RBCs is thought to be associated with a number of significant adverse effects in recipients. In adults, WBC reduction has been shown to reduce the frequency of HLA alloimmunization, CMV and HTLV infections, and febrile nonhemolytic transfusion reactions. However, neonates are unique, given that they have an immature immune system and are frequently transfused with RBCs. Thus, the aims of this systematic review were to determine whether WBC reduction of RBCs transfused to neonates decreases the transmission of CMV, reduces the ability to develop HLA antibodies, or reduces the risk of immunomodulation. In addition, nosocomial infection, mortality, and duration of stay were identified and analyzed. STUDY DESIGN AND METHODS: All studies of WBC reduction were identified by a systematic review of the literature. Studies meeting the inclusion criteria were grouped based on study outcome. Where appropriate, studies were pooled to obtain an overall measure of effect. RESULTS: Nine eligible studies were identified from the systematic literature search, and six were deemed evaluable. Two studies evaluated WBC reduction and the development of CMV, with different results. The pooled OR was 0.19 (95% Cl, 0.01-3.41), suggesting a clinical but nonsignificant effect. Two studies evaluated WBC reduction and HLA antibody development. As with CMV, the two studies were not congruent in their results. The pooled OR was 0.17 (95% Cl, 0.01-2.43). As for immunomodulation, two small studies presented evidence of a statistically significant change in lymphocyte subsets. No studies were identified with a primary objective of evaluating the impact of WBC reduction on nosocomial infection, mortality, or duration of stay. CONCLUSION: Current evidence suggests that WBC reduction may be effective in neonates; however, further studies are needed. The lack of convincing data and the significant cost of WBC reduction mandate evaluations to determine the clinical and economic impact.

Effectiveness of intensive rehabilitation on functional ability and quality of life after first total knee arthroplasty: A single-blind randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of a new intensive functional rehabilitation (IFR) program on functional ability and quality of life (QOL) in persons who underwent a first total knee arthroplasty (TKA). DESIGN: Randomized controlled trial. SETTING: Ambulatory care. PARTICIPANTS: Seventy-seven people with knee osteoarthritis. INTERVENTION: Two months after TKA, subjects were randomly assigned to either a group with IFR (n=38), who received 12 supervised rehabilitation sessions combined with exercises at home between months 2 and 4 after TKA, or to a control group (n=39), who received standard care. All participants were evaluated by a blind evaluator at baseline (2mo after TKA), immediately after IFR (2mo later; POST1), and 2 and 8 months later (POST2 and POST3). Main outcome measures The primary outcome measure with respect to effectiveness was the 6-minute walk test (6MWT) at POST2. Secondary outcome measures were the 6MWT at the other evaluations and the Western Ontario and McMaster Universities Osteoarthritis Index and Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: Subjects in the IFR group walked longer distances (range, 23-26m) in 6 minutes at the 3 POST evaluations than subjects in the control group. At POST1 and POST2, they also had less pain, stiffness, and difficulty in performing daily activities. Positive changes in QOL in favor of the IFR were found only at POST2. CONCLUSIONS: The IFR was effective in improving the short-term and mid-term functional ability after uncomplicated primary TKA. The magnitude of the IFR effect on the primary outcome was modest but consistent. More intensive rehabilitation should be promoted in the subacute recovery period after TKA, to optimize functional outcomes in the first year after surgery.

A survey of physician efficacy requirements to plan clinical trials.

PURPOSE: Eliciting physician efficacy requirements for utilizing medical treatments can be a useful means of helping plan a clinical trial. Efficacy requirements were studied for female stress urinary incontinence, where an experimental treatment (collagen injection) was compared to the standard therapy (surgery). METHODS: A self-administered questionnaire was sent to 223 North American urologists, gynecologists, and urogynecologists. An interviewer also administered a similar questionnaire to 20 other clinician-specialists. RESULTS: The response rate for the self-administered questionnaire was 48.4% (108/223). All 20 clinician-specialists who were approached for an interview consented. On average, respondents to the self-administered questionnaire indicated they would consider using collagen as the first line treatment if the absolute reduction in efficacy of collagen versus surgery was no larger than 23%. The corresponding result for the interview-questionnaire was 22%. Efficacy was measured as patient satisfaction with treatment. In the opinion of the physicians, surgery would remain the standard therapy if the reduction was greater than 34% (self-administered questionnaire), or 37% (interviewer-administered questionnaire). CONCLUSIONS: The elicitation of physician efficacy requirements provides an idea of the treatment effect that would be needed for a clinical trial to have an impact on medical practice. These requirements can be used to calculate a relevant sample size.

Oral health status and treatment satisfaction with mandibular implant overdentures and conventional dentures: a randomized clinical trial in a senior population.

PURPOSE: The purpose of this study was to compare elderly patients' satisfaction and oral health-related quality of life with mandibular two-implant overdentures and conventional dentures. MATERIALS AND METHODS: Sixty edentulous subjects aged 65 to 75 years were randomly assigned to two groups treated with maxillary conventional dentures and either a mandibular conventional denture (n = 30) or an overdenture supported by two implants with ball retainers (n = 30). Subjects rated their general satisfaction, as well as other features of their dentures (comfort, stability, ability to chew, speech, esthetics, and cleaning ability), prior to treatment and 2 months postdelivery. Changes in ratings on the original Oral Health Impact Profile (OHIP) and its short form (OHIP-EDENT) were also used as indicators of oral health-related quality of life. RESULTS: The primary outcome of this study, ratings of general satisfaction 2 months postdelivery, was significantly better in the group treated with mandibular two-implant overdentures (P = .001). In addition, the implant group gave significantly higher ratings on comfort, stability, and ability to chew. Furthermore, using OHIP-EDENT, subjects who received mandibular two-implant overdentures had significantly fewer oral health-related quality of life problems than did the conventional group. CONCLUSION: These short-term results suggest that mandibular two-implant overdentures combined with maxillary conventional dentures provide better function and oral health-related quality of life than conventional dentures.

Clinical risk factors for cytomegalovirus retinitis in patients with AIDS.

PURPOSE: To determine the clinical risk factors for cytomegalovirus (CMV) retinitis in patients with AIDS. DESIGN: A case-control study. PARTICIPANTS: The study included 120 patients in whom CMV retinitis had been diagnosed from 1990 through 1999 (cases) and 159 patients without CMV retinitis from the same period (controls). All individuals had AIDS and CD4 counts less than 50 cells/microl at the time of diagnosis of retinitis in the cases or on the corresponding date for the controls. METHODS: Clinical risk factors were determined by history or physical examination. Confounders controlled for included CD4 count, hospital center, and a series of variables to control for confounding by drug treatment. Statistical analysis was performed by multivariate logistic regression. A systematic model-building strategy was developed from assumption testing to model building to model checking. MAIN VARIABLES MEASURED: Presence of visual symptoms, retinal microinfarctions (cotton-wool spots), history of opportunistic infections, and risk factors for human immunodeficiency virus acquisition were determined and compared in both groups. RESULTS: The following clinical risk factors were significant predictors of CMV retinitis: flashing lights or floaters (odds ratio [OR], 11.42; 95% confidence interval [CI], 3.43 to 38.01), cotton-wool spots (OR, 2.90; 95% CI, 1.01 to 8.29), number of previous opportunistic infections (OR, 1.81; 95% CI, 1.24 to 2.64), previous nonocular CMV infection (OR, 82.99; 95% CI, 6.86 to 1004.58), previous Mycobacterium infection (OR, 3.41; 95% CI, 0.99 to 11.85), and homosexuality (OR, 2.83; 95% CI, 1.13 to 7.12). CONCLUSIONS: Based on this study, clinical variables have been identified that elevate the risk of CMV retinitis. These findings may be useful to clinicians and health policy experts in developing rational guidelines for screening, examination frequency, and targeted prophylaxis for CMV retinitis in patients with AIDS.