How many controls?

The majority of knowledge about fibromyalgia syndrome (FMS) derives from studies of female patients. Little is known about the clinical characteristics and treatment outcomes of male patients with FMS. In this retrospective cohort study with a prospective posttreatment follow-up, we investigated whether male patients with FMS differ from female patients in terms of 1) symptom burden, 2) psychological characteristics, and 3) clinical treatment response. We identified 263 male (4%) out of 5,541 patients with FMS completing a 3-week multimodal pain-treatment program. Male patients (51.3 ± 9.1 years) were age- and time-matched (1:4) with female patients (N = 1,052, 51.3 ± 9.0 years). Data on clinical characteristics, psychological comorbidities, and treatment responses were obtained from medical records and validated questionnaires. Levels of perceived pain, psychological comorbidity, and functional capacity were similar between genders, although male patients with FMS showed a higher prevalence of alcohol abuse. Compared to female patients, male patients experienced themselves less often as overly accommodating (Cohen’s d = −.42) but more often as self-sacrificing (d = .26) or intrusive (d = .23). Regarding pain coping, male patients were less likely to utilize mental distraction, rest- and relaxation techniques, or counteractive activities (d = .18–.27). Male patients showed a slightly worse overall response rate than women (69% vs 77%), although differences between individual outcome measures were small (d < .2). Although male and female patients in our cohort were similar in clinical presentation and treatment response, the gender-specific differences in interpersonal problems and pain coping suggest consideration of these aspects in the treatment of male patients with FMS.

Knowledge about fibromyalgia mostly derives from studies of female patients. Identifying and understanding gender-specific differences in fibromyalgia is an important roadmap in the treatment of this syndrome by focusing on specific gender aspects such as differences in interpersonal problems and pain coping mechanisms.

We study motor-vehicle collisions involving child pedestrians walking to school in Hamilton, Ontario, Canada to understand and contrast collision risks at mid-block and intersection locations. We use a matched case–control study design and apply it to intersection and mid-block locations instead of people. Cases are intersections/mid-blocks where collisions occurred and controls are locations where collisions did not occur. We match cases to controls on geography, socio-economic status and year. We use conditional logistic regression to predict the log-odds of collision risk at intersections and mid-blocks as a function of various environmental measures while controlling for volume of child pedestrian activity. Our results suggest that child pedestrian injuries at intersections are associated with intersection control type, traffic volume, and land use characteristics. In contrast, mid-block child pedestrian collisions are not associated with small scale environmental features. The results of this study suggest that some factors associated with the risk of collision differ across location types. These findings may be useful in the planning of safer walking journeys to school.

To update a 2005 review of the reasons researchers have given for the use of unequal randomisation in randomised controlled trials (RCTs).

Intervention being tested; type of study; number of participants; randomisation ratio; sample size calculation and reason given for using unequal randomisation.

Review of trials using unequal randomisation.

Cochrane library, Medline and CINAHL.

A total of 86 trials were identified. Of these 82 trials (95%) recruited patients in favour of the experimental group. Various reasons for the use of unequal randomisation were given including: gaining treatment experience; identification of adverse events; ethical; logistic and enhancing recruitment. No trial reported explicitly used it for cost-effectiveness. Most of the papers (i.e. 47, 55%) did not state why they had used unequal randomisation and only 38 trials (44%) appeared to have taken the unequal randomisation into account in their sample size calculation.

Most studies did not mention the rationale for unequal allocation, and a significant proportion did not appear to account for it in the sample size calculations. Unlike the previous review economic considerations were not stated as a rationale for its use. A number of trials used it to enhance recruitment, although this has not been tested.