Sodium-glucose co-transporter 2 (SGLT2) inhibitors, originally developed as glucose-lowering agents, have been shown to reduce heart failure hospitalizations in patients with type 2 diabetes without established heart failure, and in patients with heart failure with and without diabetes. Their role in patients with heart failure with preserved and mildly reduced ejection fraction remains unknown.

We thank Daniel Jackson and Jonathan Wessen for their helpful comments on the article.

BackgroundIdentification and knowledge of settings with high prevalence of hepatitis C virus (HCV) infection is important when aiming for elimination of HCV. The primary aim of this study was to estimate the prevalence of viremic HCV infection among Swedish prisoners. Secondary aims were to estimate the prevalence of hepatitis B surface antigen (HBsAg), human immunodeficiency virus (HIV), and the proportion who have received hepatitis B virus (HBV) vaccination.MethodsA cross-sectional study of all incarcerated persons (n = 667) at all prisons (n = 9) in Stockholm County was conducted. All prisoners are routinely offered opt-in screening for HCV antibodies (anti-HCV), HCV RNA, HBsAg, anti-HBs, anti-HBc and HIV Ag/Ab at prison in Sweden. Data on the results of these tests and the number of received HBV vaccine doses were collected from the prison medical records. The parameters of HCV RNA, anti-HCV, and occurrence of testing for HCV were analysed in multiple logistic regression models in relation to age, sex and prison security class.ResultsThe median age was 35 (IQR 26–44) years, and 93.4% were men. Seventy-one percent (n = 471) had been tested for anti-HCV, 70% (n = 465) for HBsAg and 71% (n = 471) for HIV. The prevalence of anti-HCV, HCV RNA, HBsAg and HIV Ag/Ab was 17.0, 11.5, 1.9, and 0.2%, respectively among tested persons. The proportion of prisoners who had received full HBV vaccination was 40.6% (n = 271) among all study subjects.ConclusionsThe prevalence of viremic HCV infection among Swedish prisoners in Stockholm County was 11.5%, which is high in comparison to the general population. Therefore, when aiming for the WHO goal of HCV elimination, prisons could suit as a platform for identification and treatment of HCV infection. There is a need to increase testing for blood-borne viruses and to improve vaccination coverage against HBV in Swedish prisons.

Confirmatory clinical trials comparing the efficacy of a new treatment with an active control typically aim at demonstrating either superiority or non-inferiority. In the latter case, the objective is to show that the experimental treatment is not worse than the active control by more than a pre-specified non-inferiority margin. We consider two classes of group-sequential designs that combine the superiority and non-inferiority objectives: non-adaptive designs with fixed group sizes and adaptive designs where future group sizes may be based on the observed treatment effect. For both classes, we derive group-sequential designs meeting error probability constraints that have the lowest possible expected sample size averaged over a set of values of the treatment effect. These optimized designs provide an efficient means of reducing expected sample size under a range of treatment effects, even when the separate objectives of proving superiority and non-inferiority would require quite different fixed sample sizes. We also present error spending versions of group-sequential designs that are easily implementable and can handle unpredictable group sizes or information levels. We find the adaptive choice of group sizes to yield some modest efficiency gains; alternatively, expected sample size may be reduced by adding another interim analysis to a non-adaptive group-sequential design.