Effect of early intensive multifactorial therapy compared with routine care on self-reported health status, general well-being, diabetes-specific quality of life and treatment satisfaction in screen-detected type 2 diabetes mellitus patients (ADDITION-Europe): a cluster-randomised trial

Abstract

Aims/hypothesis: The study aimed to examine the effects of intensive treatment (IT) vs routine care (RC) on patient-reported outcomes after 5 years in screen-detected diabetic patients.

Methods: In a pragmatic, cluster-randomised, parallel-group trial, 343 general practices in Denmark, Cambridge and Leicester (UK) and the Netherlands were randomised to screening for type 2 diabetes mellitus plus IT of multiple risk factors in people 40-69 years without known diabetes (n = 1,678 patients) or screening plus RC (n = 1,379 patients). Practices were randomised in a 1:1 ratio according to a computer-generated list. Diabetes mellitus was diagnosed according to WHO criteria. Exclusions were: life expectancy <1 year, housebound, pregnant or lactating, or psychological or psychiatric problems. Treatment targets for IT were: HbA1c <7.0% (53 mmol/mol), BP ≤135/85 mmHg, cholesterol <5 mmol/l in the absence of a history of coronary heart disease and <4.5 mmol/l in patients with cardiovascular (CV) disease; prescription of aspirin to people taking antihypertensive medication and, in cases of CV disease or BP >120/80 mmHg, ACE inhibitors were recommended. After 2003, the treatment algorithm recommended statins to all patients with cholesterol of ≥3.5 mmol/l. Outcome measures were: health status (Euroqol 5 Dimensions [EQ-5D]) at baseline and at follow-up; and health status (36-item Short Form Health Survey [SF-36] and Euroquol Visual Analogue Scale [EQ-VAS]), well-being (12-item Short Form of the Well-Being Questionnaire), diabetes-specific quality of life (Audit of Diabetes-Dependent Quality of Life) and satisfaction with diabetes treatment (Diabetes Treatment Satisfaction Questionnaire) at follow-up. At baseline, standardised self-report questionnaires were used to collect information. Questionnaires were completed at the same health assessment visit as the anthropometric and biochemical measurements. The patients and the staff assessing the outcomes were unaware of the group assignments. Participants were followed for a mean of 5.7 years. Outcome data were available for 1,250 participants in the intensive treatment group (74%) and 967 participants in the routine care group (70%). The estimated differences in means from the four centres were pooled using random effects meta-analysis. Baseline EQ-5D level was used as a covariate in all analyses.

Results: EQ-5D values did not change between diagnosis and follow-up, with a median (interquartile range) of 0.85 (0.73-1.00) at baseline and 0.85 (0.73-1.00) at 5 year follow-up. Health status, well-being, diabetes-specific quality of life and treatment satisfaction did not differ between the intensive treatment and routine care groups. There was some heterogeneity between centres (I 2 being between 13% [SF-36 physical functioning] and 73% [EQ-VAS]).

Conclusions/interpretation: There were no differences in health status, well-being, quality of life and treatment satisfaction between screen-detected type 2 diabetes mellitus patients receiving intensive treatment and those receiving routine care. These results suggest that intensive treatment does not adversely affect patient-reported outcomes.

Trial registration number: ClinicalTrials.gov NCT00237549 FUNDING: ADDITION-Denmark was supported by the National Health Services, the Danish Council for Strategic Research, the Danish Research Foundation for General Practice, Novo Nordisk Foundation, the Danish Centre for Evaluation and Health Technology Assessment, the Diabetes Fund of the National Board of Health, the Danish Medical Research Council and the Aarhus University Research Foundation. In addition, unrestricted grants from pharmaceutical companies were received. ADDITION-Cambridge was supported by the Wellcome Trust, the Medical Research Council, the NIHR Health Technology Assessment Programme, National Health Service R&D support funding and the National Institute for Health Research. SJG received support from the Department of Health NIHR grant funding scheme. ADDITION-Leicester was supported by Department of Health, the NIHR Health Technology Assessment Programme, National Health Service R&D support funding and the National Institute for Health Research. ADDITION-Netherlands was supported by unrestricted grants from Novo Nordisk, Glaxo Smith Kline and Merck, and by the Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht.

Figures

Fig. 1

Practice and participant flows in the ADDITION-Europe trial

Fig. 2

Mean difference in health status between the IT and RC groups after 5 years of follow-up by centre (boxes) and pooled estimates (diamonds) calculated by random effects meta-analysis. The widths of the horizontal bars and diamonds denote the 95% CI, and the box sizes indicate the relative weight in the analysis. MCS, mental component scale; PCS, physical component scale

Fig. 3

Mean difference in scores from the W-BQ12 between the IT and RC groups after 5 years of follow-up by centre (boxes) and pooled estimates (diamonds) calculated by random effects meta-analysis. The widths of the horizontal bars and diamonds denote the 95% CI, and the box sizes indicate the relative weight in the analysis

Fig. 4

Mean difference in scores from the ADDQoL questionnaire between the IT and RC groups after 5 years of follow-up by centre (boxes) and pooled estimates (diamonds) calculated by random effects meta-analysis. The widths of the horizontal bars and diamonds denote the 95% CI, and the box sizes indicate the relative weight in the analysis

Fig. 5

Mean difference in scores from the DTSQ between the IT and RC groups after 5 years of follow-up by centre (boxes) and pooled estimates (diamonds) calculated by random effects meta-analysis. The widths of the horizontal bars and diamonds denote the 95% CI, and the box sizes indicate the relative weight in the analysis