This study will examine whether significant differences across Asian ethnic groups in prevalence of chronic diseases, behavioral and psychosocial risk factors, preventive service use, and patient-portal use are masked when statistics are reported for Asians. We will use a very large cohort of adults aged 20 to 90 who were members of Kaiser Permanente Northern California for two or more years as of December 2016 to compare six Asian ethnic groups (Filipino, Chinese, Korean, Japanese, South Asian, and Southeast Asian). Electronic health record and clinical and administrative data linked to the cohort will be used to compare prevalence of chronic conditions, HEDIS (Healthcare Effectiveness Data and Information Set) performance on chronic disease management and cancer screening, frequency of smoking, frequency of obesity and exercise, and patient-portal use. Pooled data from the 2011 and 2014-15 Member Health Surveys will be used to compare Asian ethnic groups on sociodemographic characteristics, health status, and health behavior and psychosocial risks. Asian ethnic groups will also be compared with non-Hispanic white, black, and Latino adults.