Effect of chronic supplementation with methylsulfonylmethane on oxidative stress following acute exercise in untrained healthy men

Objective  This study was conducted to assess the effects of chronic daily methylsulfonylmethane (MSM) supplementation on known markers of oxidative stress following acute bouts of exercise in untrained healthy young men. Methods  Eighteen untrained men volunteered for this study. Participants were randomized in a double-blind placebo-controlled fashion into two groups: MSM (n = 9) and placebo (n = 9). The participants took supplementation or placebo daily for 10 days before running. Participants ran 14 km. The MSM supplementation was prepared in water at 50 mg/kg body weight. The placebo group received water. Serum malondialdehyde (MDA), protein carbonyl (PC) and plasma oxidized glutathione (GSSG) were measured as markers of oxidative stress. The plasma-reduced glutathione (GSH) level and the GSH/GSSG ratio were determined as markers of plasma antioxidant capacity. Key Findings  Acute exercise led to elevated levels of serum MDA, PC and plasma GSSG. MSM supplementation maintained PC, MDA and GSSG at lower levels after exercise than the placebo. The plasma level of GSH and the ratio of GSH/GSSG were significantly higher in the MSM supplemented group. Conclusions  These results suggest that chronic daily oral supplementation of MSM has alleviating effects on known markers of oxidative stress following acute bouts of exercise in healthy young men

Monitoring Quality of Care for Joint Replacements: Assessing Alternative Statistical Methods to Accurately Estimate Time to Revision

With increased longevity and as younger, more physically active patients are receiving joint replacements, it has become increasingly important to measure the failure rate for joint replacements using the cumulative incidence of revision. The most commonly applied survival analysis technique, the Kaplan-Meier (KM) method, does not account for competing risks (i.e., patient deaths) and consequently overestimates the cumulative incidence. This thesis examines alternative methods for estimating the cumulative incidence of revision using population-based cohorts of hip and knee replacements performed in Alberta and Sweden. In comparing the KM method to the cumulative incidence function, which accounts for competing risks, the KM method overestimated the cumulative incidence at each time point. The magnitude of overestimation increased with follow-up time and higher mortality rates. Application of three regression models demonstrated competing risks models require careful interpretation. Competing risks methods are recommended to accurately estimate revision rates for healthcare planning purposes.2 year

Competing risks methods are recommended for estimating the cumulative incidence of revision arthroplasty for health care planning purposes

Cumulative incidence of revision provides a measure of the failure rate of joint replacements and can be used to project demand for revisions. The most commonly applied survival analysis method (Kaplan-Meier [KM]) does not account for competing risks (eg, death). The authors compared the cumulative incidence function (CIF), a competing risks method, with the KM method through application to population-based cohorts. They measured time to revision, death, or censoring for unilateral total hip arthroplasty (THA; n=12,496) and total knee arthroplasty (TKA; n=19,172) cohorts in administrative databases in Alberta and TKAs (n=80,177) in the Swedish Knee Arthroplasty Register. The authors compared relative differences between the KM and CIF. They fitted Cox, Fine and Gray, and Royston and Parmar regression models and compared coefficients, standard errors, and P values. On sensitivity analysis, the authors included staged bilateral operations. Kaplan-Meier estimates exceeded the CIF at each time point. The magnitude of overestimation increased with follow-up time and was greatest for the Swedish cohort. At 5 years, relative differences between KM and CIF estimates for the Alberta THA and TKA and Swedish TKA cohorts were 1.8%, 2.3%, and 3.8%, respectively. These differences increased to 3.1%, 5.8%, and 8.2%, respectively, at 9 years, reaching 39.1% at 20 years (Swedish cohort). On sensitivity analysis (including staged bilateral operations), the Fine and Gray subdistribution hazard ratio differed from the Cox and Royston and Parmar hazard ratios. When the frequency of competing risks is high, competing risks methods are recommended to obtain accurate cumulative incidence estimates for informing health care planning and decision making

Assessing the quality of economic evaluations of clinical nurse specialists and nurse practitioners: A systematic review of cost-effectiveness

A limited number of randomized controlled trials (RCTs) including economic analysis have supported the cost-effectiveness of nurse practitioners and clinical nurse specialists delivering care in a variety of settings. Our objective was to examine the quality of economic evaluations in this body of literature using the Quality of Health Economic Studies (QHES) tool, and highlight which questions of the quality assessment tool are being addressed adequately or require further attention within this body of literature. Of 43 RCTs included in our systematic review, the majority (77%) fell in the poor study quality quartile with an average total QHES score of 39 (out of 100). Only three studies (7%) were evaluated as high quality. Inter-rater agreement (prior to consensus process) was high (83% agreement). Four criteria for the quality of economic evaluations were consistently addressed: specification of clear, measurable objectives; pre-specification of subgroups for subgroup analyses; justified conclusions based on study results; and disclosure of study funding source. A clear statement of the primary outcome measures, incremental analysis, and assessment of uncertainty were often unclear or missing. Due to poor methodological quality, we currently lack a solid evidence base to draw clear conclusions about the cost-effectiveness of nurse practitioners and clinical nurse specialists. Higher quality economic evaluations are required to inform these questions. Keywords: Clinical nurse specialists, Cost-effectiveness, Economic evaluation, Nurse practitioners, Review, systematic, Quality assessmen