Editor—The United Kingdom Prospective Diabetes Study has shown over 10 years of follow up that people with newly diagnosed type 2 diabetes can maintain excellent glycaemic control (concentrations of haemoglobin A1c of 7%) and that this can significantly reduce microvascular complications.1 It has also shown that strict blood pressure control can significantly reduce mortality as well as microvascular and macrovascular complications among these people.2 The study group thus answered its primary research questions. The design of the study meant that several secondary questions could not be answered convincingly.3 Several lessons in ethics and public health can, however, be learnt.
The fact that the comparison group maintained a comparatively low concentration of haemoglobin A1c (7.9%) over 10 years of follow up means that the researchers were ethical to the point of risking a null finding. In contrast, in their enthusiasm to establish the efficacy of specific treatment(s) some investigators replace standard drug treatment with an inactive placebo.4 The researchers continuously adapted the intervention to changes in scientific knowledge and clinical practice, which is reasonable and justifiable in a 20 year trial that chooses to adhere to sound ethical principles.
The study was conducted in primary healthcare settings rather than specialist centres or university hospitals, and the results are therefore likely to be closer to clinical practice than those from other large clinical trials would be.5 By simulating clinical practice as closely as possible, the study group has given data on effectiveness that are more suitable for translating into public health practice than are efficacy data collected in controlled and ideal environments. In including a blood pressure control trial,2 the investigators acknowledged that complications of diabetes are multifactorial in aetiology; glycaemic control is but one aspect. The vast burden of complications on the population can be effectively and efficiently tackled only if risk factors such as high blood pressure, dyslipidaemia, and smoking receive at least as much attention as glycaemic control. The study results may have their biggest influence in better management of blood pressure among people with type 2 diabetes.2 The fact that conventional glycaemic treatment for people in the comparison group resulted in a relatively low haemoglobin A1c concentration suggests that some attributes (for example, universal health care, emphasis on primary care, relationship between primary and specialist care, patient education) of the British model of health care may be particularly suitable for managing chronic diseases. Countries such as the United States may benefit from examining some of these attributes and modifying their approaches to the management of chronic diseases accordingly.