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Previous observational studies have suggested an association between coffee intake and reduced risk for death, but these studies did not distinguish between coffee consumed with sugar or artificial sweeteners and coffee consumed without.To evaluate the associations of consumption of sugar-sweetened, artificially sweetened, and unsweetened coffee with all-cause and cause-specific mortality.Prospective cohort study.Data were extracted from the UK Biobank.A total of 171 616 participants (mean age, 55.6 years [SD, 7.9]) without cardiovascular disease (CVD) or cancer at baseline were eligible. Baseline demographic, lifestyle, and dietary data from the UK Biobank were used, with follow-up beginning in 2009 and ending in 2018.Dietary consumption of sugar-sweetened, artificially sweetened, and unsweetened coffee was self-reported. All-cause, cancer-related, and CVD-related mortality were estimated.During a median follow-up of 7.0 years, 3177 deaths were recorded (including 1725 cancer deaths and 628 CVD deaths). Cox models with penalized splines showed U-shaped associations of unsweetened coffee, sugar-sweetened coffee, and artificially sweetened coffee with mortality. Compared with nonconsumers, consumers of various amounts of unsweetened coffee (0 to 1.5,1.5 to 2.5,2.5 to 3.5,3.5 to 4.5, and4.5 drinks/d) had lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors, with respective hazard ratios of 0.79 (95% CI, 0.70 to 0.90), 0.84 (CI, 0.74 to 0.95), 0.71 (CI, 0.62 to 0.82), 0.71 (CI, 0.60 to 0.84), and 0.77 (CI, 0.65 to 0.91); the respective estimates for consumption of sugar-sweetened coffee were 0.91 (CI, 0.78 to 1.07), 0.69 (CI, 0.57 to 0.84), 0.72 (CI, 0.57 to 0.91), 0.79 (CI, 0.60 to 1.06), and 1.05 (CI, 0.82 to 1.36). The association between artificially sweetened coffee and mortality was less consistent. The association of coffee drinking with mortality from cancer and CVD was largely consistent with that with all-cause mortality. U-shaped associations were also observed for instant, ground, and decaffeinated coffee.Exposure assessed at baseline might not capture changes in intake over time.Moderate consumption of unsweetened and sugar-sweetened coffee was associated with lower risk for death.National Natural Science Foundation of China, Young Elite Scientist Sponsorship Program by CAST, and Project Supported by Guangdong Basic and Applied Basic Research Foundation.

Background Risk for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to close contacts of infected persons has not been well estimated. Objective To evaluate the risk for transmission of SARS-CoV-2 to close contacts in different settings. Design Prospective cohort study. Setting Close contacts of persons infected with SARS-CoV-2 in Guangzhou, China. Participants 3410 close contacts of 391 index cases were traced between 13 January and 6 March 2020. Data on the setting of the exposure, reverse transcriptase polymerase chain reaction testing, and clinical characteristics of index and secondary cases were collected. Measurement Coronavirus disease 2019 (COVID-19) cases were confirmed by guidelines issued by China. Secondary attack rates in different settings were calculated. Results Among 3410 close contacts, 127 (3.7% [95% CI, 3.1% to 4.4%]) were secondarily infected. Of these 127 persons, 8 (6.3% [CI, 2.1% to 10.5%]) were asymptomatic. Of the 119 symptomatic cases, 20 (16.8%) were defined as mild, 87 (73.1%) as moderate, and 12 (10.1%) as severe or critical. Compared with the household setting (10.3%), the secondary attack rate was lower for exposures in health care settings (1.0%; odds ratio [OR], 0.09 [CI, 0.04 to 0.20]) and on public transportation (0.1%; OR, 0.01 [CI, 0.00 to 0.08]). The secondary attack rate increased with the severity of index cases, from 0.3% (CI, 0.0% to 1.0%) for asymptomatic to 3.3% (CI, 1.8% to 4.8%) for mild, 5.6% (CI, 4.4% to 6.8%) for moderate, and 6.2% (CI, 3.2% to 9.1%) for severe or critical cases. Index cases with expectoration were associated with higher risk for secondary infection (13.6% vs. 3.0% for index cases without expectoration; OR, 4.81 [CI, 3.35 to 6.93]). Limitation There was potential recall bias regarding symptom onset among patients with COVID-19, and the symptoms and severity of index cases were not assessed at the time of exposure to contacts. Conclusion Household contact was the main setting for transmission of SARS-CoV-2, and the risk for transmission of SARS-CoV-2 among close contacts increased with the severity of index cases. Primary funding source Guangdong Province Higher Vocational Colleges and Schools Pearl River Scholar Funded Scheme.