Objectives. To estimate the incidence, characteristics and predictors of infections in patients with PM and DM. Methods. The medical records of 192 PM/DM patients followed up in a tertiary teaching medical centre from 1999 to 2008 were retrospectively reviewed. Results. Seventy-six episodes of major infection, defined as infections requiring >1 week of treatment with anti-microbial agents, occurred in 53 (27.6%) patients, and 15 (7.8%) patients had two or more episodes. The incidence rate of major infections was 11.1 episodes per 100 patient-years in PM/DM patients. Aspiration pneumonia [n (%) = 16 (21.1)] was the leading cause of major infections, followed by opportunistic infection [n (%) = 14 (18.4)]. A variety of pathogens were isolated, mainly including Staphylococcus aureus, Klebsiella, Escherichia coli, Salmonella and Mycobacterium. Overall patient survival rates were 85.0% at 1 year, 78.0% at 5 years and 78.0% at 10 years. However, after one episode of major infection, survival rates decreased to 84.7% at 30 days and 68.3% at 1 year. Multivariate analysis indicated that independent predictors of major infection were age >45 years at PM/DM onset [odds ratio (OR) 5.26; 95% CI 2.01, 13.77; P = 0.001], presence of arthritis/arthalgia (OR 2.59; 95% CI 1.12, 6.02; P = 0.027), co-present interstitial lung disease (OR 7.24; 95% CI 2.67, 19.65; P < 0.001), current use of AZA (OR 6.07; 95% CI 2.39, 15.42; P < 0.001) or IVIG (OR 6.33; 95% CI 1.50, 26.77; P = 0.012). Conclusions. This study underlines the high frequency of major infections in PM/DM, which is significantly detrimental to patient survival rates. Close follow-up of PM/DM patients with risk factors for developing major infections is mandatory.

Predicting complex disease risks on the basis of individual genomic profiles is an advancing field in human genetics^1,2. However, most genetic studies have focused on populations of European ancestry, creating a global imbalance in precision medicine and underscoring the need for genomic research in non-European groups^3,4. The Taiwan Precision Medicine Initiative recruited more than half a million Taiwanese residents, providing a large dataset of genetic profiles and electronic medical record data for people with Han Chinese ancestry. Using extensive phenotypic data, we conducted comprehensive genomic analyses across the medical phenome with individuals genetically similar to Han Chinese reference populations. These analyses identified population-specific genetic risk variants and new findings for various complex traits. We developed polygenic risk scores, demonstrating strong predictive performance for conditions such as cardiometabolic diseases, autoimmune disorders, cancers and infectious diseases. We observed consistent findings in an independent dataset, Taiwan Biobank, and among people of East Asian ancestry in the UK Biobank and the All of Us Project. The identified genetic risks accounted for up to 10.3% of the overall health variation in the Taiwan Precision Medicine Initiative cohort. Our approach of characterizing the phenome-wide genomic landscape, developing population-specific risk-prediction models, assessing their performance and identifying the genetic effect on health serves as a model for similar studies in other diverse study populations.