OBJECTIVEType 2 diabetes is associated with an increased risk of several types of cancer and with reduced survival after cancer diagnosis. We examined the hypotheses that survival after a diagnosis of solid-tumor cancer is reduced in those with diabetes when compared with those without diabetes, and that treatment with metformin influences survival after cancer diagnosis.RESEARCH DESIGN AND METHODSData were obtained from >350 U.K. primary care practices in a retrospective cohort study. All individuals with or without diabetes who developed a first tumor after January 1990 were identified and records were followed to December 2009. Diabetes was further stratified by treatment regimen. Cox proportional hazards models were used to compare all-cause mortality from all cancers and from specific cancers.RESULTSOf 112,408 eligible individuals, 8,392 (7.5%) had type 2 diabetes. Cancer mortality was increased in those with diabetes, compared with those without (hazard ratio 1.09 [95% CI 1.06–1.13]). Mortality was increased in those with breast (1.32 [1.17–1.49]) and prostate cancer (1.19 [1.08–1.31]) but decreased in lung cancer (0.84 [0.77–0.92]). When analyzed by diabetes therapy, mortality was increased relative to nondiabetes in those on monotherapy with sulfonylureas (1.13 [1.05–1.21]) or insulin (1.13 [1.01–1.27]) but reduced in those on metformin monotherapy (0.85 [0.78–0.93]).CONCLUSIONSThis study confirmed that type 2 diabetes was associated with poorer prognosis after incident cancer, but that the association varied according to diabetes therapy and cancer site. Metformin was associated with survival benefit both in comparison with other treatments for diabetes and in comparison with a nondiabetic population.

Patients with type 2 diabetes initiated with metformin monotherapy had longer survival than did matched, non-diabetic controls. Those treated with sulphonylurea had markedly reduced survival compared with both matched controls and those receiving metformin monotherapy. This supports the position of metformin as first-line therapy and implies that metformin may confer benefit in non-diabetes. Sulphonylurea remains a concern.

OBJECTIVETo assess the association of compliance with treatment (medication and clinic appointments) and all-cause mortality in people with insulin-treated type 2 diabetes.RESEARCH DESIGN AND METHODSData were extracted from U.K. general practice records and included patients (N = 15,984) who had diagnostic codes indicative of type 2 diabetes or who had received a prescription for an oral antidiabetic agent and were treated with insulin. Records in the 30 months before the index date were inspected for clinical codes (recorded at consultation) indicating medication noncompliance or medical appointment nonattendance. Noncompliance was defined as missing more than one scheduled visit or having at least one provider code for not taking medications as prescribed. Relative survival postindex date was compared by determining progression to all-cause mortality using Cox proportional hazards models.RESULTSThose identified as clinic nonattenders were more likely to be smokers, younger, have higher HbA1c, and have more prior primary care contacts and greater morbidity (P < 0.001). Those identified as medication noncompliers were more likely to be women (P = 0.001), smokers (P = 0.014), and have higher HbA1c, more prior primary care contacts, and greater morbidity (all P < 0.001). After adjustment for confounding factors, medication noncompliance (hazard ratio 1.579 [95% CI 1.167–2.135]), clinic nonattendance of one or two missed appointments (1.163 [1.042–1.299]), and clinic nonattendance of greater than two missed appointments (1.605 [1.356–1.900]) were independent risk factors for all-cause mortality.CONCLUSIONSMedication noncompliance and clinic nonattendance, assessed during routine care by primary care physicians or their staff, were independently associated with increased all-cause mortality in patients with type 2 diabetes receiving insulin.

Summary Background Epidemiology data regarding hidradenitis suppurativa (HS) are conflicting and prevalence estimates vary 80‐fold, from 0·05% in a population‐based study to 4%. Objectives To assess the hypothesis that previous population‐based studies underestimated true HS prevalence by missing undiagnosed cases. Methods We performed a population‐based observational and case–control study using the U.K. Clinical Practice Research Datalink (CPRD) linked to hospital episode statistics data. Physician‐diagnosed cases in the CPRD were identified from specific Read codes. Algorithms identified unrecognized ‘proxy’ cases, with at least five Read code records for boils in flexural skin sites. Validation of proxy cases was undertaken with general practitioner (GP) questionnaires to confirm criteria‐diagnosed cases. A case–control study assessed disease associations. Results On 30 June 2013, 23 353 physician‐diagnosed HS cases were documented in 4 364 308 research‐standard records. In total, 68 890 proxy cases were identified, reduced to 10 146 criteria‐diagnosed cases after validation, extrapolated from 107 completed questionnaires (61% return rate). Overall point prevalence was 0·77% [95% confidence interval (CI) 0·76–0·78%]. An additional 18 417 cases had a history of one to four flexural skin boils. In physician‐diagnosed cases, odds ratios (ORs) for current smoker and obesity (body mass index > 30 kg m‐2) were 3·61 (95% CI 3·44–3·79) and 3·29 (95% CI 3·14–3·45). HS was associated with type 2 diabetes, Crohn disease, hyperlipidaemia, acne and depression, and not associated with ulcerative colitis or polycystic ovary syndrome. Conclusions Contrary to results of previous population‐based studies, HS is relatively common, with a U.K. prevalence of 0·77%, one‐third being unrecognized, criteria‐diagnosed cases using the most stringent disease definition. If individuals with probable cases are included, HS prevalence rises to 1·19%.

Summary Hidradenitis suppurativa (HS) is a long‐term skin disease affecting young adults, causing multiple boils in skin crease sites such as the armpits and groins. The boils are painful, may produce pus and leave disfiguring scars. How common HS is remains controversial, with recent reports using USA medical insurance data suggesting about 0.1% of the population is affected, which is lower than European studies using self‐reported questionnaires (completed by the patient). This may be because insurance databases miss undiagnosed cases. Our study team based in the UK aimed to use UK electronic data recorded by General Practitioners (GPs) to identify known and previously undiagnosed cases of HS. We identified undiagnosed cases by looking for patients who had seen their GP for at least 5 skin boils and validated their diagnosis by sending some of the GPs a questionnaire to double‐check. Out of 4.3 million patients in the GP database, we found 23,000 diagnosed HS patients and 10,000 undiagnosed patients, showing that 0.77% of the UK population has HS. Including probable cases, who had 1‐4 skin boil consultations, the figure rises to 1.19%. Comparing people with HS to similar people without HS, there are higher rates of smoking and obesity (both 3 times more common), as well as type 2 diabetes, Crohn's disease, raised fat levels in the blood, acne, high blood pressure and depression. However a link was not found between HS and ulcerative colitis or polycystic ovary syndrome. In conclusion, we found that HS is relatively common, nearly 10 times more common than the estimates using USA insurance data. People with HS have higher rates of risk factors for heart disease and stroke and so checking for these conditions is important.