Merging self-reported with technically sensed data for tracking mobility behavior in a naturalistic intervention study. Insights from the GISMO study.

Sound exposure data are central for any intervention study. In the case of utilitarian mobility, where studies cannot be conducted in controlled environments, exposure data are commonly self-reported. For short-term intervention studies, wearable devices with location sensors are increasingly employed. We aimed to combine self-reported and technically sensed mobility data, in order to provide more accurate and reliable exposure data for GISMO, a long-term intervention study. Through spatio-temporal data matching procedures, we are able to determine the amount of mobility for all modes at the best possible accuracy level. Self-reported data deviate ±10% from the corrected reference. Derived modal split statistics prove high compliance to the respective recommendations for the control group (CG) and the two intervention groups (IG-PT, IG-C). About 73.7% of total mileage was travelled by car in CG. This share was 10.3% (IG-PT) and 9.7% (IG-C), respectively, in the intervention groups. Commuting distances were comparable in CG and IG, but annual mean travel times differ between x ¯  = 8,458 min (σ = 6,427 min) for IG-PT, x ¯  = 8,444 min (σ = 5,961 min) for IG-C, and x ¯  = 5,223 min (σ = 5,463 min) for CG. Seasonal variabilities of modal split statistics were observable. However, in IG-PT and IG-C no shift toward the car occurred during winter months. Although no perfect single-method solution for acquiring exposure data in mobility-related, naturalistic intervention studies exists, we achieved substantially improved results by combining two data sources, based on spatio-temporal matching procedures.

Use and costs of anti-secretory and cardiovascular co-medication in osteoarthritis patients treated with selective or non-selective NSAIDS.

OBJECTIVE: This study aims to compare use and costs of anti-secretory and cardiovascular co-medication in osteoarthritis patients treated with selective or non-selective NSAIDs. METHOD: A retrospective study examined Belgian patients aged 65 years or more who suffer from osteoarthritis and are chronic users of selective NSAIDs (n=1,376) or non-selective NSAIDs (n=8,482). A before-and-after analysis compared drug use and costs between period 1 (first 6 months of 2002) and period 2 (several 1-year periods stretching over 2003-2004). A cohort analysis contrasted patients taking selective NSAIDs with patients taking non-selective NSAIDs. MAIN OUTCOME MEASURES: Anti-secretory co-medication included histamine H2-receptor antagonists and proton pump inhibitors. Cardiovascular co-medication referred to cardiac glycosides, anti-arrhythmics, anti-thrombotics, anti-angina drugs, anti-hypertensive drugs and serum-lipid-reducing drugs. Volume of drug use was expressed as number of packages and costs were computed in Euro. RESULTS: The volume of anti-secretory co-medication increased by 36% with selective NSAIDs and by 55% with non-selective NSAIDs between periods 1 and 2. Cardiovascular co-medication rose by 18% with selective NSAIDs and by 12% for non-selective NSAIDs. Focusing on patients who did not take anti-secretory co-medication in period 1, patients taking selective NSAIDs were just as likely to start anti-secretory co-medication in period 2 as patients taking non-selective NSAIDs (odds ratio: 1.05; 95% confidence interval: 0.90-1.23). Patients taking selective NSAIDs were just as likely to start cardiovascular co-medication as patients taking non-selective NSAIDs (odds ratio: 1.03; 95% confidence interval: 0.78-1.36). Annual costs of treating osteoarthritis in ambulatory care amounted to 756 with selective NSAIDs and 416 with non-selective NSAIDs. This originated from higher acquisition costs (278 vs. 24 ) and higher costs of co-medication (477 vs. 392 ) with selective NSAIDs. CONCLUSIONS: The use of selective and non-selective NSAIDs is accompanied by a higher use of co-medication over time. The increase in anti-secretory co-medication was more prominent with non-selective NSAIDs. The rise in cardiovascular co-medication was more pronounced with selective NSAIDs. Treatment of osteoarthritis with selective NSAIDs is more expensive than with non-selective NSAIDs in terms of acquisition costs and costs of co-medication.