Humans

Stillbirth, defined as fetal death at 20 or more weeks of gestation or 350 g or greater in birth weight, is a tragic outcome for families and clinicians.1 Stillbirth affects approximately 5.7 per 1000 births in the US—equivalent to 21 000 annually—and can occur antenatally (83%) or intrapartum (17%).2 This rate has remained relatively stable over the past 2 decades, despite substantial reductions in infant and childhood mortality.3,4 Stillbirth prevention is complex because many cases of stillbirth are unexplained, and there are substantial disparities in incidence by geographic region, socioeconomic status, and maternal race.5

Importance Tai chi is a type of exercise recommended for knee osteoarthritis, but access to in-person tai chi can be limited.

Objective To evaluate the effects of an unsupervised multimodal online tai chi intervention on knee pain and function for people with knee osteoarthritis.

Design, Setting, and Participants The RETREAT study was a 2-group superiority randomized clinical trial enrolling participants who met clinical criteria for knee osteoarthritis in Australian communities from August 2023 and November 2024.

Interventions Participants in the control group received access to a purpose-built website containing information about osteoarthritis and exercise benefits. Participants in the intervention group received the My Joint Tai Chi intervention comprising access to the same website plus tai chi information, a 12-week unsupervised video-based Yang-style tai chi program, and encouragement to use an app to facilitate program adherence.

Main Outcomes and Measures Changes in knee pain during walking (Numeric Rating Scale; range 0-10 with higher scores indicating greater pain) and difficulty with physical function (Western Ontario and McMaster Universities Osteoarthritis Index; range 0-68 with higher scores indicating greater dysfunction) during 12 weeks. Secondary outcomes included another knee pain measure, sport and recreation function, quality of life, physical and mental well-being, fear of movement, self-efficacy, balance confidence, positive activated affect, sleep quality, global improvement, and oral medication use.

Results Of 2106 patients screened, 178 met inclusion criteria and were randomized, 89 (mean [SD] age, 61.0 [8.7] years; 66 female [74%] and 23 [26%] male participants) to the control group and 89 (mean [SD] age, 62.1 [7.3] years; 59 [66%] female and 30 male [34%] participants) to the tai chi intervention. Of the total, 170 (96%) completed both of the primary outcomes at 12 weeks. The tai chi group reported greater improvements in knee pain (control, −1.3; tai chi, −2.7; mean difference, −1.4 [95% CI, −2.1 to −0.7] units; P < .001) and function (control, −6.9; tai chi, −12.0; mean difference, −5.6 [95% CI, −9.0 to −2.3] units; P < .001) compared to the control group. More participants in the tai chi than in the control group achieved a minimal clinically important difference in pain (73% vs 47%; risk difference, 0.3; 95% CI, 0.1 to 0.4; P < .001) and function (72% vs 52%; risk difference, 0.2; 95% CI, 0.1 to 0.3; P = .007). Between-group differences for most secondary outcomes favored tai chi, including another knee pain measure, sport and recreation function, quality of life, physical and mental well-being, global improvement, pain self-efficacy, and balance confidence. No associated serious adverse events were reported.

Conclusions and Relevance This randomized clinical trial found that this unsupervised multimodal online tai chi intervention improved knee pain and function compared with the control at 12 weeks. This free-to-access web-based intervention offers an effective, safe, accessible, and scalable option for guideline-recommended osteoarthritis exercise.

Measles is a highly contagious virus with a primary case reproduction number (i.e., the average number of secondary cases per case patient) of 12 to 18. It is currently spreading rapidly owing to reduced measles vaccination coverage, which is due primarily to the disruption of local immunization programs by the coronavirus disease 2019 (Covid-19) pandemic and of growing vaccine hesitancy.1 Since 2024, all World Health Organization (WHO) regions have reported increased numbers of measles cases, with 395,521 laboratory-confirmed measles cases reported in 2024 and 16,147 reported during the first 2 months of 2025.2 Patients in more than half the reported cases were hospitalized, so the true number is probably much higher.3
This review covers clinical presentations and complications of measles, current recommendations, and the epidemiologic background of measles. It also addresses the current debates on immunization and the treatment of measles and presents information on the origins of the various measles vaccines and updates on measles diagnostic testing and molecular genotypes.

Importance: Approximately 27% of adults in the US and Canada report having ever used cannabis for medical purposes. An estimated 10.5% of the US population reports using cannabidiol (CBD), a chemical compound extracted from cannabis that does not have psychoactive effects, for therapeutic purposes.

Observations: Conditions for which cannabinoids have approval from the US Food and Drug Administration include HIV/AIDS-related anorexia, chemotherapy-induced nausea and vomiting, and certain pediatric seizure disorders. A meta-analysis of randomized clinical trials reported a small but significant reduction in nausea and vomiting from various causes (eg, chemotherapy, cancer) when comparing prescribed cannabinoids (eg, dronabinol, nabilone) with placebo or active comparators (eg, alizapride, chlorpromazine; standardized mean difference [SMD], -0.29 [95% CI, -0.39 to -0.18]). A meta-analysis of randomized clinical trials among patients with HIV/AIDS reported that cannabinoids had a moderate effect on increasing body weight compared with placebo (SMD, 0.57 [95% CI, 0.22 to 0.92]). Evidence-based guidelines do not recommend the use of inhaled or high-potency cannabis (≥10% or 10 mg Δ9-tetrahydrocannabinol [Δ9-THC]) for medical purposes. High-potency cannabis compared with low-potency cannabis use is associated with increased risk of psychotic symptoms (12.4% vs 7.1%) and generalized anxiety disorder (19.1% vs 11.6%). A meta-analysis of observational studies reported that 29% of individuals who used cannabis for medical purposes met criteria for cannabis use disorder. Daily inhaled cannabis use compared with nondaily use was associated with an increased risk of coronary heart disease (2.0% vs 0.9%), myocardial infarction (1.7% vs 1.3%), and stroke (2.6% vs 1.0%). Evidence from randomized clinical trials does not support the use of cannabis or cannabinoids for most conditions for which it is promoted, such as acute pain and insomnia. Before considering cannabis or cannabinoids for medical use, clinicians should consult applicable institutional, state, and national regulations; evaluate for drug-drug interactions; and assess for contraindications (eg, pregnancy) or conditions in which risks likely outweigh benefits (eg, schizophrenia or ischemic heart disease). For patients using cannabis or cannabinoids for treatment of medical conditions, clinicians should discuss harm reduction strategies, including avoiding concurrent use with alcohol or other central nervous system depressants such as benzodiazepines, using the lowest effective dose, and avoiding use when driving or operating machinery.

Conclusions and relevance: Evidence is insufficient for the use of cannabis or cannabinoids for most medical indications. Clear guidance from clinicians is essential to support safe, evidence-based decision-making. Clinicians should weigh benefits against risks when engaging patients in informed discussions about cannabis or cannabinoid use.