In their interesting research, Giorda et al(1) state that “Receiving specialist care itself increased survival, but was far more effective when combined with the fulfillment of existing screening [follow-up] guidelines (GCI)”. For GCI adherence was chosen as indicator measure which includes the annual assessment of A1C and at least two assessments from among eye examinations, total serum cholesterol, and microalbuminuria.
The Authors’ conclusion is based on the comparison of mortality and morbidity outcomes in four groups of all the residents in the city of Torino (Italy) with a diagnosis of diabetes, with a 4-year follow-up, in relation to four care levels:
A: General practitioner (GP) and specialist, and fair fulfillment of GCI (reference, and standard of care in the Region)
B: GP and specialist, without GCI
C: GP without specialist, and fair fulfillment of GCI
D: GP without specialist and without GCI, i.e. only GP.
Indeed, the data of Table 3(1) show that neither mortality nor major cardiovascular events differed significantly between level A and C, and that GP without specialist but with GCI had substantially the same outcomes than level A (for instance RR of all-cause mortality 0.95 (IC 95% 0.81-1.12)); thus not having “intermediate” outcomes between level A and level D.
Therefore, the influencing factor seems to be the GCI, as quality-of-care indicator, and not the referral to a diabetes clinic. Actually, the diabetes clinics without GCI (level B) had worse outcomes in trend (and for all-cause mortality significantly) than GP with GCI but without specialist (level C), with the only exception of CHD.
Interestingly, this somewhat is similar to the results of some meta-analysis of RCTs(2-4), in which targeting intensive versus standard glycaemic control shows some benefit in CHD and non fatal myocardial infarction, but no significant effect on all-cause or cardiovascular mortality; on the contrary a more intensive glycaemic control shows a trend to a higher all-cause and cardiovascular mortality.
Moreover, in the Discussion the authors (1) state something that seems unsupported by their own data. For instance, they claim that “there appear to be a protective effect of aggressive diabetes treatment on cancer development”, while tabled data show that GP with GCI but without specialist (level C), arguably with treatments less aggressive compared with those of diabetes clinics, have indeed a trend to a lower cancer mortality (RR 0.86) compared to level A. The same level C shows also a borderline lower cancer mortality compared with level B, where the use of the newer and more aggressive treatments, typical of Specialist settings, is more likely, in contrast with a moderate, more conservative, attitude usually adopted by a large part of GPs.
Another claim not supported by the published data(1) is that “Consistently with other studies, diabetes clinic referral … emerges as a good predictor of better long-term prognosis, being itself associated with a reduction of the probability of death …”. Instead, the tabulated data show that the risk of death in level C (GP with GCI but without specialist) is lower (albeit not significantly) compared to level A, and significantly lower if compared to level B (specialist without both GP and GCI).
As the Authors themselves noted, the observational nature of the study hampers any causal inference, so, for instance, there may be other reasons for the poor results of patients in level D (only GP), including unbalanced baseline characteristics perhaps not completely adjusted for. Anyway the superior benefits of diabetes clinics do no seem to be supported by the data of this observational research.
An erroneous presentation of this results could be wrongly used by health care providers, shifting the care of many diabetic patients from primary care to diabetes clinics, instead of implementing a reasonable and feasible use of the GCI. This could increase the costs without adding benefit to the care of diabetic patients, in particular the elderly and those with multimorbidity.


Alberto Donzelli, MD, Service of Education for Appropriateness and Evidence Based Medicine - Local Health Unit, ASL of Milan, Italy

Alessandro Nobili, MD, Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy

Mauro Tettamanti, MSc, Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy


1. Giorda C, Picariello R, Nada E, et al. The Impact of Adherence to Screening Guidelines and of Diabetes Clinics Referral on Morbidity and Mortality in Diabetes. PLoS ONE 2012; 7:e33839

2. Turnbull FM et al. Intensive glucose control and macrovascular outcomes in type 2 diabetes. Diabetologia 2009; 52:2288

3. Boussageon R et al. Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials. BMJ 2011;343:d4169

4. Hemmingsen B et al. Intensive glycaemic control for patients with type 2 diabetes: systematic review with meta-analysis and trial sequential analysis of randomised clinical trials. BMJ 2011;343:d6898