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Although physical activity reduces mortality and morbidity, injuries associated with activity may increase both short- and long-term musculoskeletal disability. On the basis of basic science and injury epidemiology studies, authors have made conclusions about cause and effect (causal inferences) and have suggested various interventions to decrease the rate of injuries. However, recent advances in epidemiology suggest that the regression/stratification approach to adjustment for confounding does not provide an appropriate foundation for causal inference; therefore, hypotheses based on traditional analyses may be misleading. The purpose of this article is to provide an overview of the basic concepts of injury epidemiology related to causes, risk factors, and confounding, and to conceptually explain the more recent advances that allow for appropriate interpretations of cause and effect. [ABSTRACT FROM AUTHOR]

PURPOSE: To determine whether increased physical activity 1 month after deep vein thrombosis (DVT) led to worsening of venous symptoms and signs within the subsequent 3 months. METHODS: By a multicenter prospective cohort study of patients with acute DVT, we used validated questionnaires at baseline, 1 month, and 4 months post-DVT for each exposure, using the Godin Questionnaire to measure physical activity, the VEINES-QOL to measure disease severity, and the postthrombotic syndrome (PTS) scale to measure symptoms and signs usually attributed to sequelae of DVT. RESULTS: Of 301 patients followed for 4 months, 25% were inactive and 25% were only mildly active before their DVT. In univariate analysis, physical activity at 1 month was not associated with a change in PTS score between 1 month and 4 months (P=0.42). After adjusting for the potential confounders of age, sex, pre-DVT physical activity, and disease severity at 1 month, the results suggested that higher physical activity levels at 1 month may be protective against worsening of the PTS score over the subsequent 3 months. Compared with those who were inactive at 1 month, the adjusted OR was 0.93 (95%CI: 0.47, 1.87) for mildly to moderately active persons, and 0.52 (95%CI: 0.24, 1.15) for highly active persons. Among patients who were active pre-DVT (N=220), 55.5% had returned to their previous levels of physical activity or greater within 4 months. CONCLUSIONS: For most persons, exercise at 1 month post-DVT does not appear to worsen venous symptoms and signs over the subsequent 3 months, and more than 50% resume their usual level of activity within 4 months. [ABSTRACT FROM AUTHOR]

OBJECTIVE:: The purpose of this article was to evaluate the clinical and basic science evidence surrounding the hypothesis that stretching improves performance. DATA SOURCES AND SELECTION:: MEDLINE and Sport Discus were searched using MeSH and textwords for English-language and French-language articles related to stretching and performance (or performance tests). Additional references were reviewed from the bibliographies and from citation searches on key articles. All articles related to stretching and performance (or performance tests) were reviewed. MAIN RESULTS:: Of the 23 articles examining the effects of an acute bout of stretching, 22 articles suggested that there was no benefit for the outcomes isometric force, isokinetic torque, or jumping height. There was 1 article that suggested improved running economy. Of 4 articles examining running speed, 1 suggested that stretching was beneficial, 1 suggested that it was detrimental, and 2 had equivocal results. Of the 9 studies examining the effects of regular stretching, 7 suggested that it was beneficial, and the 2 showing no effect examined only the performance test of running economy. There were none that suggested that it was detrimental. CONCLUSIONS:: An acute bout of stretching does not improve force or jump height, and the results for running speed are contradictory. Regular stretching improves force, jump height, and speed, although there is no evidence that it improves running economy. [ABSTRACT FROM AUTHOR]

PURPOSE: Rubber band ligation therapy for symptomatic hemorrhoidal disease has been used for many years and is a well-accepted treatment modality, but information on longterm outcome is limited. Our goals were to determine safety and long-term efficacy of this treatment. METHODS: A retrospective chart review of patients undergoing rubber band ligatures for symptomatic internal hemorrhoids in a single practice was conducted. Information on presenting symptoms, number of bands applied, response to therapy, complications encountered, length of follow-up, interval to recurrent symptoms when applicable, and subsequent therapy were documented. Supplemental information was obtained from telephone follow-up. Outcome was categorized as success or failure, in which success was defined as: permanent relief of symptoms for follow-up period; marked improvement in symptomatology with rare manifestation of bleeding (≤1/month); symptom relief for a limited period of time (≥100 days), and failure was defined as: modest improvement (decreased but not relief of symptoms); or no improvement in symptoms. RESULTS: A total of 805 patients underwent 2,114 rubber band ligatures. Most common presenting symptoms were bleeding in 731 patients (90.8 percent) and prolapsing in 382 patients (47.5 percent). The median number of bands placed was two (range, 1–17). The median time between bandings was 4.7 (range, 1.1–35.6) weeks. Median follow-up time was 1,204 (range, 14–9,571) days. Excluding 104 patients lost to follow-up (never returned after initial treatment), success was obtained in 70.5 percent (494/701) and failure in 29.5 percent (207/701) of patients. Success rates were similar for all degrees of hemorrhoids. Hemorrhoidal disease requiring the placement of four or more bands was associated with a trend in higher failure rates and greater need for subsequent hemorrhoidectomy. Complications per treatment series included bleeding (2.8 percent), thrombosed external hemorrhoids (1.5 percent), and bacteremia (0.09 percent). Higher bleeding rates were encountered with the use of acetylsalicylic acid/nonsteroidal anti-inflammatory drugs and warfarin. Time to recurrence was less with subsequent treatment courses. Treatment of recurrent symptoms with rubber band ligation resulted in success rates of 73.6, 61.4, and 65 percent for first, second, and third recurrences respectively. This resulted in a cumulative success rate of 80.2 percent for this method of treatment. CONCLUSIONS: Rubber band ligatures are safe and effective therapy for symptomatic internal hemorrhoids. It can be used to treat all degrees of hemorrhoids with similar effectiveness. The likelihood of success is lower if more than four bands are needed to eliminate symptoms. The use of acetylsalicylic acid/nonsteroidal anti-inflammatory drugs and warfarin is associated with higher bleeding rates. Rubber band ligatures for recurrence of symptoms is effective; however, time to recurrence is less with subsequent treatments. [ABSTRACT FROM AUTHOR]

PURPOSE: The value of specialization has frequently been challenged by many health care institutions and providers. This review was conducted to determine whether there were any outcome differences in the management of fistulas complicating diverticulitis. METHODS: We conducted an historical cohort study using hospital charts of all cases of fistulas complicating diverticulitis that were operated on in four university-affiliated hospitals between 1975 and 1995, There were 122 patients, with 37 under the care of fully trained colorectal surgeons and 85 under the care of general surgeons. RESULTS: There were no significant differences in patient demographics, preoperative comorbidities, or the number of preoperative diagnostic investigations between the two groups. The colorectal surgeons performed more intraoperative ureteral stenting (Colorectal Surgery 55.5 percent vs. General Surgery 24.4 percent, P = 0.001). The general surgeons performed more initial diverting Hartmann's and colostomy procedures (Colorectal Surgery 5.4 percent vs. General Surgery 27 percent, P = 0.013). The patients in the General Surgery group had longer preoperative lengths of stay (median Colorectal Surgery 3 (range, 1-28) days vs. General Surgery 8 (range, 0-29) days; P < 0.001), longer postoperative lengths of stay (median Colorectal Surgery 11 (range. 5-40) days vs. General Surgery 14 (range, 2-80) days; P = 0.001), and longer total lengths of stay (median Colorectal Surgery 14 (range, 6-62) days vs. General Surgery 24 (range, 6-100) days; P < 0.001). The patients in the General Surgery group experienced a higher rate of wound infections (Colorectal Surgery 5.4 percent vs. General Surgery 12.9 percent), and a larger proportion of them experienced complications (Colorectal Surgery 27 percent vs. General Surgery 41.2 percent). CONCLUSIONS: We conclude that specialization in colon and rectal surgery contributed to an improved outcome, with a lower rate of diverting procedures, a shorter hospital stay, and a lower rate of complications. [ABSTRACT FROM AUTHOR]

Immortal time may arise in survival analyses when individuals are assigned to treatment strategies based on post-eligibility information or selected based on post-assignment eligibility criteria. Selection based on eligibility criteria applied after treatment assignment results in immortal time when the analysis starts the follow-up at assignment. Misclassification of assignment to treatment strategies based on treatment received after eligibility results in immortal time when the treatment strategies are not distinguishable at the start of follow-up. Target trial emulation prevents the introduction of immortal time by explicitly specifying eligibility and assignment to the treatment strategies, and by synchronizing them at the start of follow-up. We summarize analytic approaches that prevent immortal time when longitudinal data are available to emulate the target trial from the time of treatment assignment. The term "immortal time bias" suggests that the source of the bias is the immortal time, but it is selection or misclassification that generates the immortal time, leading to bias., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To explore the accuracy of combined neurology expert forecasts in predicting primary endpoints for trials., Methods: We identified one major randomized trial each in stroke, multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) that was closing within 6 months. After recruiting a sample of neurology experts for each disease, we elicited forecasts for the primary endpoint outcomes in the trial placebo and treatment arms. Our main outcome was the accuracy of averaged predictions, measured using ordered Brier scores. Scores were compared against an algorithm that offered noncommittal predictions., Results: Seventy-one neurology experts participated. Combined forecasts of experts were less accurate than a noncommittal prediction algorithm for the stroke trial (pooled Brier score = 0.340, 95% subjective probability interval [sPI] 0.340 to 0.340 vs 0.185 for the uninformed prediction), and approximately as accurate for the MS study (pooled Brier score = 0.107, 95% confidence interval [CI] 0.081 to 0.133 vs 0.098 for the noncommittal prediction) and the ALS study (pooled Brier score = 0.090, 95% CI 0.081 to 0.185 vs 0.090). The 95% sPIs of individual predictions contained actual trial outcomes among 44% of experts. Only 18% showed prediction skill exceeding the noncommittal prediction. Independent experts and coinvestigators achieved similar levels of accuracy., Conclusion: In this first-of-kind exploratory study, averaged expert judgments rarely outperformed noncommittal forecasts. However, experts at least anticipated the possibility of effects observed in trials. Our findings, if replicated in different trial samples, caution against the reliance on simple approaches for combining expert opinion in making research and policy decisions., (© 2020 American Academy of Neurology.)

A 36-yr-old man presents with left ulnar-side wrist pain during an ice hockey game that prevented him from playing hockey or golf. There was no acute mechanism of injury. The usual clinical examination revealed only minimal tenderness and minimal pain with resisted wrist extension. Careful attention to precipitating factors led to testing resisted wrist extension with the forearm fully supinated, which reliably reproduced the intensity of the patient's symptoms, and a diagnosis of extensor carpi ulnaris tendinopathy. A literature review suggested three additional special tests (two were positive) and management. However, a standard of care has yet been established because neither the tests nor the management has been properly validated through research, thus leaving the management of this condition as an art.

Although meta-analyses provide summary effect estimates that help advise patient care, patients often want to compare their overall health to the general population. The Harvard Cancer Risk Index was published in 2004 and uses risk ratio estimates and prevalence estimates from original studies across many risk factors to provide an answer to this question. However, the published version of the formula only uses dichotomous risk factors and its derivation was not provided. The objective of this brief report was to provide the derivation of a more general form of the equation that allows the incorporation of risk factors with three or more levels.

The intention-to-treat analysis evaluates the causal effect of treatment assignment in a randomized controlled trial; however, participants do not always adhere to assigned treatment and the intention-to-treat effect may differ from the effect of treatment receipt. Although more recent adherence-based methods assess a well-defined causal effect of receiving treatment, adherence is assumed to be dichotomized as all or none. This approach can lack precision in the real world because adherence is a complex and heterogeneous phenomenon. In this article, we illustrate a simple method that provides estimates of bounds on the causal effect of full adherence to treatment in the presence of partial adherence. We first define three types of partial adherence (delayed, partial-dose, posttreatment). We then use casual diagrams to show that categorizing partial adherence as nonadherence in a sensitivity analysis can lead to a violation of the exclusion restriction principle. Finally, we apply recently published sensitivity analyses related to principal stratification that allow for creating bound estimates around the causal effect of treatment in the presence of partial adherence.

There are claims in the literature that the risk difference is a more heterogeneous measure than the odds ratio or risk ratio. These claims are based on surveys of meta-analyses showing that tests reject the null hypothesis of homogeneity more often for the risk difference than for the ratio measures. Discussions of this point have neglected the fact that homogeneity tests can have different levels of statistical power (i.e., different probabilities of rejecting the null when it is false) across different scales. We give hypothetical examples in which there is arguably equal heterogeneity across risk difference and odds ratio measures but in which the risk difference homogeneity test rejects more often, and therefore has higher power, than the odds ratio homogeneity test. These examples suggest that current empirical evidence for the claim that the risk difference is more heterogeneous is not at present satisfactory. Further research could consider other approaches to empirical comparisons of the heterogeneity of the three measures.

Background: : The threat of being sued is a concern for many anesthesiologists. This paper asks whether litigation brought against anesthesiologists is associated with the age of the anesthesiologist., Methods: : Institutional research ethics approval was granted. We obtained billing data for all procedures performed by specialist anesthesiologists stratified into three age groups (less than 51, 51-64, and 65 and older) from British Columbia, Quebec, and Ontario for the 10-yr period from Jan. 1, 1993 to Dec. 31, 2002. We also obtained all litigations (including disability weighted claims) handled by the Canadian Medical Protective Association during the same time period in which the Canadian Medical Protective Association experts considered the anesthesiologist cited to be at least partially responsible for the adverse event leading to the complaint., Results: : In univariate analysis with the less than 51 age group as the reference category, the litigation rate ratio for the 51-64 age group was 1.14 (95% CI: 0.99-1.32) and for the 65 and older age group was 1.50 (95% CI: 1.14-1.97). Our analyses using disability weighted claims showed the 51-64 group to have 1.31 (95% CI: 0.95-1.80) and 65 and older group to have 1.94 (95% CI: 1.41-2.67) relative increase in disability compared to the less than 51 age group., Conclusions: : We found a higher frequency of litigation and a greater severity of injury in patients treated by anesthesiologists in the 65 and older group. The reasons for these findings should become an active field of research.

Study Design: A quasi-experimental study was conducted., Objective: To compare intraindividual differences between trunk flexion isometric force, fatigue during isometric contraction (isometric fatigue), and fatigue during sit-ups (dynamic fatigue)., Summary of Background Data: Trunk flexion force and trunk flexion fatigue commonly are used to assess trunk flexion fitness. The use of one test is appropriate only if the tests are highly correlated., Methods: This study measured force and either isometric fatigue (time to task failure, n = 79) or dynamic fatigue (number of sit-ups in 2 minutes, n = 73) in self-selected, healthy secondary school (I-III) subjects. In 15 subjects, both isometric and dynamic fatigue were measured., Results: After control was used for upper body mass, the R2(adj) was 0.34 between isometric force and isometric fatigue, 0.31 between isometric force and dynamic fatigue was, and 0.27 between dynamic fatigue and isometric fatigue. Including gender in the model did not affect the results., Conclusions: The lack of a high correlation between trunk flexion isometric fatigue, dynamic fatigue, and isometric force suggests that health care professionals should be careful to select the test that answers their particular needs or question.

The study objectives were to determine the incidence of musculoskeletal pain in a cohort of adolescents and whether work is a risk factor for its development. 502 students in the seventh to ninth grades responded to a questionnaire at three times over a 12-month period, addressing musculoskeletal health and lifestyle factors. Annual incidence of musculoskeletal pain was 38%. Adolescents who worked developed pain more than those who did not work (adjusted odds ratio (OR): 1.62, 95% confidence interval (CI): 0.96, 2.76). Those who worked in white-collar jobs were at a higher risk of developing pain than those in blue-collar jobs or childcare. The conclusion that work is associated with musculoskeletal pain development in adolescents implies that implementation of prevention strategies in the workplace should include adolescents who work.

Study Design: A prospective, repeated measures cohort study with high school students was conducted in Montreal, Canada., Objective: To determine the incidence of neck and upper limb pain and associated risk factors in a cohort of adolescents., Summary of Background Data: Neck and upper limb pain is frequent in adolescents and may be associated with repetitive motion from certain activities such as playing music, working, and engaging in sports activities., Methods: For this study, 502 students in the seventh to ninth grades in three schools were assessed. Data were collected at three times 6 months apart over a 12-month period. Students responded to a questionnaire addressing musculoskeletal health and lifestyle factors and were measured for height and weight. Neck or upper limb pain occurring at least once a week in the preceding 6 months was defined as the outcome. Multivariate methods were used to model the repeated measures dichotomous outcome as a function of engaging in physical activity, working, or playing a musical instrument, adjusted for covariates., Results: The cumulative annual incidence of neck and upper limb pain was 28.4%. The risk factors for neck and upper limb pain were working (adjusted odds ratio, 1.89; 95% confidence interval, 1.11-3.32) and lower mental health score (adjusted odds ratio, 1.68; 95% confidence interval, 1.19-2). Students involved in childcare were at a higher risk for the development of pain (adjusted odds ratio, 2.25; 95% confidence interval, 1.18-4.29)., Conclusions: Neck and upper limb pain is common in teenagers. Sports involvement and music participation were not risk factors for the development of neck and upper limb pain. However, pain was more likely to develop in adolescents who worked than in students who had a lower mental health score.