SHORT COMMUNICATION The effectiveness of structured personal care of type 2 diabetes on recurrent outcomes: a 19 year follow-up of the study Diabetes Care in General Practice (DCGP) Hanna Lundström & Volkert Siersma & Anni B. Sternhagen Nielsen & John Brodersen & Susanne Reventlow & Per K. Andersen & Niels de Fine Olivarius Received: 3 November 2013 /Accepted: 10 February 2014 /Published online: 6 March 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract Aims/hypothesis The estimation of effect size in clinical trials commonly disregards recurrent outcomes. We investigated the effectiveness of a complex intervention on recurrent outcomes in patients with type 2 diabetes. Methods In the Diabetes Care in General Practice (DCGP) randomised controlled trial, 1,381 patients newly diagnosed with type 2 diabetes were randomised to 6 years of structured personal care or routine care (ClinicalTrials.gov NCT01074762). The trial had 19 years of registry-based follow-up and was analysed with Cox regression models. Repeated occurrences in the same patient of outcomes (any diabetes-related endpoint, myocardial infarction [MI], stroke, peripheral vascular disease and microvascular disease) were accounted for with the Wei, Lin and Weissfeld method. Results As previously shown, the intervention reduced the rates of first occurrence of both MI and any diabetes-related endpoint. However, for all outcomes, the HR for a second event showed a statistically non-significant tendency to be increased. We estimated a combined HR for all marginal failure times, regardless of whether they were first, second or later events. This showed that the intervention had no effect on the rate of any of the outcomes, including MI (HR 0.89, 95% CI 0.76, 1.05) and any diabetes-related endpoint (HR 0.98, 95% CI 0.87, 1.09). Conclusions/interpretation In the DCGP study, a smaller pro- portion of patients who received structured care experienced a first occurrence of MI or any diabetes-related endpoint com- pared with patients who received routine care. However, the patients who received structured care tended to experience more recurrent outcomes, so the total outcome rate was not affected by the intervention. Keywords Any diabetes-related endpoint . Myocardial infarction . Randomised controlled trial . Recurrent events . Type 2 diabetes . Wei, Lin and Weissfeld method Abbreviations ADDITION Anglo–Danish–Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care CVD Cardiovascular disease DCGP Diabetes Care in General Practice MI Myocardial infarction WLW Wei, Lin and Weissfeld Introduction Improved survival from cardiovascular disease (CVD) has made it more common for patients to experience new occur- rences of adverse events after the occurrence of a first event, and diabetes patients have an increased risk of developing a subsequent cardiovascular event compared with the general population [1]. Such recurrent events result in increased use of healthcare services and medication, as well as decreased qual- ity of life for the patient. Therefore, standard analysis using a Cox regression model, with its strict focus on time to first Electronic supplementary material The online version of this article (doi:10.1007/s00125-014-3204-1) contains peer-reviewed but unedited supplementary material, which is available to authorised users. H. Lundström : V. Siersma : A. B. S. Nielsen : J. Brodersen : S. Reventlow : N. de Fine Olivarius (*) The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, PO Box 2099, 1014 Copenhagen K, Denmark e-mail: olivarius@sund.ku.dk P. K. Andersen Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark Diabetologia (2014) 57:1119–1123 DOI 10.1007/s00125-014-3204-1