The online case-crossover study is a novel approach to study triggers for recurrent disease flares

OBJECTIVES: To evaluate the feasibility of conducting an online case-crossover study of triggers for recurrent disease flares. METHODS: We conducted an online case-crossover study of triggers for recurrent flares using gout as a paradigm. We constructed a Web site and recruited individuals with history of gout via the Internet. We confirmed gout diagnosis by reviewing each subject's medical records. We collected via the Internet exposure information during the intercritical period using a scheduled Control-period Questionnaire, and prior to recurrent gout attacks using a Hazard-period Questionnaire. RESULTS: Over 10 months we recruited 197 subjects with a history of gout from 41 states and the District of Columbia. We obtained medical records from 172 subjects. All participants had experienced at least one recurrent attack and filled out required questionnaires. The median time between the date of an attack and the date of logging on to the Web site was 2 days. The incidence rate of recurrent gout attacks was 1.03 per person-year. Longer disease duration and presence of comorbidities appeared to increase the risk of recurrent flares. CONCLUSION: The results of this study demonstrate that a case-crossover study can be successfully conducted through the Internet. This approach has broad applicability to other diseases typified by recurrent attacks.     

Cardiovascular Risks of Probenecid Versus Allopurinol in Older Patients With Gout

Background

Patients with gout are at an increased risk of cardiovascular (CV) disease including myocardial infarction (MI), stroke, and heart failure (HF).

Do radiographic disease and pain account for why people with or at high risk of knee osteoarthritis do not meet physical activity guidelines?

Objective

Knee osteoarthritis (OA) and pain are assumed to be barriers to meeting physical activity guidelines, but this has not been formally evaluated. The purpose of this study was to determine the proportions of people with and those without knee OA and knee pain who meet recommended physical activity levels through walking.

Methods

We performed a cross‐sectional analysis of community‐dwelling adults from the Multicenter Osteoarthritis Study who had or who were at high risk of knee OA. Participants wore a StepWatch activity monitor to record steps per day for 7 days. The proportion of participants who met the recommended physical activity levels was defined as those accumulating ≥150 minutes per week at ≥100 steps per minute in bouts lasting ≥10 minutes. These proportions were also determined for those with and those without knee OA, as classified by radiography and by severity of knee pain.

Results

Of the 1,788 study participants (mean ± SD age 67.2 ± 7.7 years, mean ± SD body mass index 30.7 ± 6.0 kg/m², 60% women), lower overall percentages of participants with radiographic knee OA and knee pain met recommended physical activity levels. However, these differences were not statistically significant between those with and those without knee OA; 7.3% and 10.1% of men (P = 0.34) and 6.3% and 7.8% of women (P = 0.51), respectively, met recommended physical activity levels. Similarly, for those with moderate/severe knee pain and those with no knee pain, 12.9% and 10.9% of men (P = 0.74) and 6.7% and 11.0% of women (P = 0.40), respectively, met recommended physical activity levels.

Conclusion

Disease and pain have little impact on achieving recommended physical activity levels among people with or at high risk of knee OA.