Dapp 2011

Methods	Purpose: to assess the effects of health risk appraisal, personal reinforcement and quality circles for older people to improve preventative care and health behaviour Design: RCT (patients of solo GPs individually randomly assigned by computer to intervention or control). The 21 solo GPs were allocated to 3 clusters of GPs matched by age, gender and qualification Duration of study: recruitment over a 9‐month period. Follow‐up at 1 year (duration of intervention not stated) Interval between intervention and when outcome was measured: follow‐up at 1 year (duration from end of intervention not stated) Power computation: 763 in intervention and 1525 required in control to detect 30% difference in preventive care or health behaviour, alpha = 0.05, power = 80%, assuming 20% preventive behaviour in controls and 20% drop‐out Statistics: generalised estimating equations; for missing data multiple imputations
Participants	Country: Germany Setting: 21 solo GP practices in Hamburg Eligible participants: (health status): 500 GP practices in Hamburg, 21 agreed to participate; each practice provided completed list of ≥ 60, and "eligibles" from practices who returned brief questionnaire and consent form were randomised (total n eligibles not stated); 2580 randomised and 746 who were not randomised were placed in a "concurrent comparison" group Age: avg 72 Gender: 62% f
Interventions	Intervention 1: health risk appraisal, individualised recommendations, health information, reinforcement by home visit or group sessions Control: usual care (but GPs had received training to care for the intervention group patients) Comparison group: usual care, no training provided to GPs Co‐interventions: none
Outcomes	Outcome measured: % influenza vaccination (and 8 other preventive care outcomes and 6 health behaviours) Time points reported in the study: follow‐up 1 year, time from end of intervention to follow‐up not stated
Notes	Funding
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer based at independent centre (patients individually randomised within solo GP practices, GPs were allocated ‐ 7 to intervention, 7 to control and 7 to "concurrent comparison" group)
Allocation concealment (selection bias)	Unclear risk	No statement
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Blinding not possible as treating GPs received summary statements about patients as part of intervention
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Total eligibles not stated; 2580 baseline in RCT (878 intervention, 1702 control), baseline characteristics similar, 746 in "concurrent comparison" group; at 1 year follow‐up 587 (70.6%) and 1376 (83.8%) in control group returned questionnaire; no differential attrition analysis
Selective reporting (reporting bias)	Low risk	No selective reporting