Lars Backlund

Elevated plasma semicarbazide‐sensitive amine oxidase (SSAO) activity in Type 2 diabetes mellitus complicated by retinopathy

Aims To measure plasma semicarbazide‐sensitive amine oxidase (SSAO) activities and detect retinopathy in Type 2 diabetes mellitus (DM).

New blindness in diabetes reduced by more than one-third in Stockholm County

To monitor changes over time in the incidence of blindness among people with diabetes, referrals (mentioning diabetes) to all vision rehabilitation centres in Stockholm County (1995 population 1 725 756) during 1981–1995 were registered. A mass mailing to people with diabetes in 1989 urged them to have their eyes examined. Mobile fundus photography teams initiated early diagnosis of diabetic retinopathy in primary health care in 1990. Referrals with diabetes and blindness, defined (WHO, ICD 10) as best‐corrected visual acuity (VA) of the better eye less than 3/60 (0.05), occurred for 172 persons (7.6 % of those referred with diabetes). During 1981–1985, 93 were referred (95 % confidence interval 75 to 114); 1986–1990, 51 (38 to 67); 1991–1995, 28 (19 to 41). Five‐year average annual incidence rate of referrals with blindness was reduced by 47 % from 1.2 to 0.63 to 0.33 per 100 000 population. Mean yearly reduction during 1981–1995 was 11 % (8 to 15 %), 11.5 % (8 to 15 %) if blindness was defined as in the UK (VA 3/60 or less), and 7 % (4 to 9 %) for legal blindness (VA 6/60 or less); test for trend p  < 0.001 (Poisson regression analysis). This is the first report of reduction in a geographical region of a proxy measure for new blindness in diabetes by one‐third or more, attaining one of the main targets of the St Vincent Declaration.

Follow-up of plasma semicarbazide-sensitive amine oxidase activity and retinopathy in Type 2 diabetes mellitus

Plasma activity of the enzyme semicarbazide-sensitive amine oxidase (SSAO) is high in diabetes. Production of angiotoxic substances (an aldehyde, hydrogen peroxide, and ammonia) in vessel walls is catalysed by SSAO, suggesting a role for SSAO in the development of complications of diabetes. The objective of the present study was to follow up plasma SSAO activity (measured radiometrically), HbA(1c) (using ion exchange chromatography), and retinopathy (by fundus photography) after 2.8 years, in 34 patients with Type 2 diabetes. We also measured urinary levels of an SSAO substrate, methylamine, by fluorometric high-performance liquid chromatography (HPLC). As at baseline, plasma SSAO activity was now higher in subjects with retinopathy (mean 19.5) than in subjects without retinopathy (mean 16.0), 95% confidence interval (CI) for difference 0.6-6.3 nmol benzylamine ml(-1) plasma h(-1). SSAO activity had not changed significantly since baseline, mean difference -1.65 and 95% CI for difference -3.76 to 0.46 nmol benzylamine ml(-1) plasma h(-1). Mean HbA(1c) level remained higher for patients with retinopathy (now 7.9%) compared to those without retinopathy (6.1%), 95% CI for difference 0.6-3.0%. Comparing baseline and the present study, retinopathy was nonproliferative; level had worsened for five and improved for two patients. Urinary methylamine/creatinine ratio was lower in the group of patients with retinopathy (mean 0.99) than in those without retinopathy (mean 1.78), 95% CI for difference 0.1-1.5 microg mg(-1). The results of the present study are compatible with a role for SSAO in the development of diabetic retinopathy.

Early detection of diabetic retinopathy by a mobile retinal photography service working in partnership with primary health care teams

Community‐wide fundus photography was organized for early detection of diabetic retinopathy (DR) by mobile teams. High‐quality three‐field Kodachrome fundus photography, performed according to the London Protocol through dilated pupils was offered free of charge to primary care; images were taken in the community and assessed centrally. Data are presented from the first 80 primary health care centres (PHCCs) participating, serving 990 000 (about 60 %) of inhabitants in Stockholm County. Beginning in 1990, 6863 diabetes patients were invited by PHCCs; 5490 (80 %) attended. We reached 77 % of persons with known diabetes; only 37 % had had their eyes examined during the preceding 2 years. For 97 % of patients, images were assessable. DR was present in 34 % of patients (non‐proliferative DR not requiring further assessment 29 %, non‐proliferative DR requiring further assessment 1.1 %, proliferative DR 0.5 % and macular involvement 3.6 %). Re‐examination after 2 years was offered to 64 %; follow‐up photography after 1 year to 24 %. Fluorescein angiography and/or photocoagulation treatment was performed in 3.6 %. This method of early diagnosis is feasible, acceptable, and reached twice as many patients as did the usual referral‐based system of care. We now plan to extend this service to cover the whole county. Copyright

Time trends in statin utilisation and coronary mortality in Western European countries

Objectives To determine whether there is a relation between statin utilisation and coronary heart disease (CHD) mortality in populations with different levels of coronary risk, and whether the relation changes over time. Design Ecological study using national databases of dispensed medicines and mortality rates. Setting Western European countries with similar public health systems. Main outcome measures Population CHD mortality rates (rate/100 000) as a proxy for population coronary risk level, and statin utilisation expressed as Defined Daily Dose per one Thousand Inhabitants per Day (DDD/TID), in each country, for each year between 2000 and 2012. Spearmans correlation coefficients between CHD mortality and statin utilisation were calculated. Linear regression analysis was used to assess the relation between changes in CHD mortality and statin utilisation over the years. Results 12 countries were included in the study. There was a wide range of CHD mortality reduction between the years 2000 and 2012 (from 25.9% in Italy to 57.9% in Denmark) and statin utilisation increase (from 121% in Belgium to 1263% in Denmark). No statistically significant relations were found between CHD mortality rates and statin utilisation, nor between changes in CHD and changes in statin utilisation in the countries over the years 2000 and 2012. Conclusions Among the Western European countries studied, the large increase in statin utilisation between 2000 and 2012 was not associated with CHD mortality, nor with its rate of change over the years. Factors different from the individual coronary risk, such as population ageing, health authority programmes, guidelines, media attention and pharmaceutical industry marketing, may have influenced the large increase in statin utilisation. These need to be re-examined with a greater emphasis on prevention strategies.

GPs' decisions on drug treatment for patients with high cholesterol values: a think-aloud study.

BackgroundThe purpose was to examine how General Practitioners (GPs) use clinical information and rules from guidelines in their decisions on drug treatment for high cholesterol values.MethodsTwenty GPs were presented with six case vignettes and were instructed to think aloud while successively more information about a case was presented, and finally to decide if a drug should be prescribed or not. The statements were coded for the clinical information to which they referred and for favouring or not favouring prescription.ResultsThe evaluation of clinical information was compatible with decision-making as a search for reasons or arguments. Lifestyle-related information like smoking and overweight seemed to be evaluated from different perspectives. A patients smoking favoured treatment for some GPs and disfavoured treatment for others.ConclusionsThe method promised to be useful for understanding why doctors differ in their decisions on the same patient descriptions and why rules from the guidelines are not followed strictly.

Statistical and Psychological Models of Doctorsâ Judgments of HeartPatients

Using participant data from the medical domain, the robustness of logistic regression (LR) with different cue inclusion levels and two fast and frugal (F&F) models in terms of predictive accuracy and frugality were tested. Two data sets based on judgments of verbally described patients were used: Heart failure (66 analysts), and Hyperlipidemia (38 analysts). In both data sets, when the models were cross-validated, there was a significant decrease in predictive accuracy for all models, especially when all cues were used in LR. The other models had about equal predictive accuracy, also when comparisons were made with actual diagnoses, with a slight advantage for LR in the Heart failure study. LR using the 5% inclusion level was more frugal than F&F. These results emphasize the importance of using cross-validation and of choosing the proper significance levels for cue inclusion and when comparing different judgment models in medical decision making and other fields.