EditorialsHow should we employ multidimensional indices of COPD? Ideally, they should serve to work towards 'optimal COPD care', based on the concept that here-and-now goals should be integrated with goals to improve long-term outcomes and reduce future risk.1 However, this integration has (until recently) been overlooked, largely because multidimensional indices have usually been developed in selected patient groups and thus lack external validity in the community.In this issue of the PCRJ, Josefin Sundh and colleagues present a large study assessing the merits of the DOSE (dyspnea, obstruction, smoking, exacerbations) index in predicting mortality in both primary and secondary care patients.2 This is an important paper, since it adds knowledge to the existing applicability of DOSE which previously has been shown to predict hospitalisation, respiratory failure and exacerbation risk. 3 The authors investigated 1,111 COPD patients aged 34-75 years, randomly selected from 70 Swedish primary and secondary care centres. 562 patients had complete data on all DOSE index components, i.e. MRC dyspnoea scale, forced expiratory volume in 1 second (FEV1) expressed as percent predicted (FEV1 %pred), smoking status, and exacerbation rate. Over the course of five years, 116 patients (20.6%) died. Mortality was higher in patients with a DOSE index score >4 (42.4%) than for lower scores (11.0%) (p<0.0001). Compared with a DOSE index score of 0-3, the hazard ratio for mortality was 3.48 (95% CI 2.32 to 5.22) for a score of 4-5, and 8.00 (95% CI 4.67 to 13.7) for a score of 6-8. Thus, the DOSE index has now been shown to be associated with mortality in COPD patients in both primary and secondary care, and can be used to assess prognosis in addition to other clinically relevant issues.Originally, DOSE was designed as a predictor of health status, whereas both BODE (BMI, Obstruction, Dyspnoea, Exercise) and ADO (Age, Dyspnoea, Obstruction) were derived as predictors of mortality. ADO has the disadvantage that it is affected by age; younger people with worse COPD based on MRC or FEV1 score better than their older counterparts. This is counterintuitive, since one would expect younger people with advanced COPD to have more serious disease than older people.4 BODE has been studied extensively, yet has the major practical drawback that it requires a 6-minute walking test. This stems from its original development in a rehabilitation setting. However, the majority of COPD patients are managed in primary care where this test is not usually performed -although it could be, provided trained personnel and a 30m hallway were available.To use any given index in primary care it should be able to identify individuals with the highest current burden of disease who are at risk of future morbidity and mortality. General criteria for the use of an index in routine clinical practice are that it should be: (i) simple to record and calculate, (ii) the component items should be easy to assess and record, (iii) the component items should be clinically imp...