de Winter MA, Büller HR, Carrier M, et al; VTE-PREDICT study group. Recurrent venous thromboembolism and bleeding with extended anticoagulation: the VTE-PREDICT risk score. Eur Heart J. 2023;44:1231-1244. 36648242.

Gearry R, Fukudo S, Barbara G, et al. Consumption of 2 green kiwifruits daily improves constipation and abdominal comfort-results of an international multicenter randomized controlled trial. Am J Gastroenterol. 9 Jan 2023. [Epub ahead of print]. 36537785.

Navaneethan SD, Zoungas S, Caramori ML, et al. Diabetes management in chronic kidney disease: synopsis of the KDIGO 2022 clinical practice guideline update. Ann Intern Med. 2023;176:381-387. 36623286.

The COVID-19 vaccines were developed and rigorously evaluated in randomized trials during 2020. However, important questions, such as the magnitude and duration of protection, their effectiveness against new virus variants, and the effectiveness of booster vaccination, could not be answered by randomized trials and have therefore been addressed in observational studies. Analyses of observational data can be biased because of confounding and because of inadequate design that does not consider the evolution of the pandemic over time and the rapid uptake of vaccination. Emulating a hypothetical "target trial" using observational data assembled during vaccine rollouts can help manage such potential sources of bias. This article describes 2 approaches to target trial emulation. In the sequential approach, on each day, eligible persons who have not yet been vaccinated are matched to a vaccinated person. The single-trial approach sets a single baseline at the start of the rollout and considers vaccination as a time-varying variable. The nature of the confounding depends on the analysis strategy: Estimating "per-protocol" effects (accounting for vaccination of initially unvaccinated persons after baseline) may require adjustment for both baseline and "time-varying" confounders. These issues are illustrated by using observational data from 2 780 931 persons in the United Kingdom aged 70 years or older to estimate the effect of a first dose of a COVID-19 vaccine. Addressing the issues discussed in this article should help authors of observational studies provide robust evidence to guide clinical and policy decisions.

Pittas AG, Kawahara T, Jorde R, et al. Vitamin D and risk for type 2 diabetes in people with prediabetes: a systematic review and meta-analysis of individual participant data from 3 randomized clinical trials. Ann Intern Med. 2023;176:355-363. 36745886.

In 2022, COVID-19 remained the infectious disease at the top of most internal medicine physicians' minds. However, it was not the only infectious disease that was the topic of clinically relevant research that year. This article highlights some important infectious disease evidence unrelated to COVID-19 that was published in 2022. The literature was screened for sound new evidence relevant to internal medicine specialists and subspecialists whose focus of practice is not infectious diseases. The publications highlighted relate to various organisms in different patient populations. One article provides insight into the role of Helicobacter pylori eradication in the treatment of functional dyspepsia. The descriptive epidemiology of bacterial (Staphylococcus aureus) and viral (mpox) infections are the focus of 2 other articles. Several articles address the management of resistant and difficult-to-treat infections: multidrug-resistant gram-negative infections, resistant HIV-1, rifampin-resistant tuberculosis, cryptococcal meningitis, and invasive fungal infection in the setting of neutropenia. Another article provides data on effective HIV preexposure prophylaxis in women, an understudied population. Finally, given the urgent need to reduce inappropriate use of antibiotics, an article on antibiotic stewardship for hospitalized patients with presumed sepsis in a non-intensive care unit setting is also included.

A growing number of older persons in developing countries live entirely alone and are physically, mentally, and financially vulnerable.