Linking cohort-based data with electronic health records: a proof-of-concept methodological study in Hong Kong.

OBJECTIVES: Data linkage of cohort-based data and electronic health records (EHRs) has been practised in many countries, but in Hong Kong there is still a lack of such research. To expand the use of multisource data, we aimed to identify a feasible way of linking two cohorts with EHRs in Hong Kong. METHODS: Participants in the 'Children of 1997' birth cohort and the Chinese Early Development Instrument (CEDI) cohort were separated into several batches. The Hong Kong Identity Card Numbers (HKIDs) of each batch were then uploaded to the Hong Kong Clinical Data Analysis and Reporting System (CDARS) to retrieve EHRs. Within the same batch, each participant has a unique combination of date of birth and sex which can then be used for exact matching, as no HKID will be returned from CDARS. Raw data collected for the two cohorts were checked for the mismatched cases. After the matching, we conducted a simple descriptive analysis of attention deficit hyperactivity disorder (ADHD) information collected in the CEDI cohort via the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour Scale (SWAN) and EHRs. RESULTS: In total, 3473 and 910 HKIDs in the birth cohort and CEDI cohort were separated into 44 and 5 batches, respectively, and then submitted to the CDARS, with 100% and 97% being valid HKIDs respectively. The match rates were confirmed to be 100% and 99.75% after checking the cohort data. From our illustration using the ADHD information in the CEDI cohort, 36 (4.47%) individuals had ADHD-Combined score over the clinical cut-off in the SWAN survey, and 68 (8.31%) individuals had ADHD records in EHRs. CONCLUSIONS: Using date of birth and sex as identifiable variables, we were able to link the cohort data and EHRs with high match rates. This method will assist in the generation of databases for future multidisciplinary research using both cohort data and EHRs.

Spillover Effects of Maternal Chronic Disease on Children's Quality of Life and Behaviors Among Low-Income Families.

BACKGROUND: Mothers with chronic diseases may have spillover effects on their children. OBJECTIVE: The aim of this study was to estimate the spillover effects of mothers with chronic disease on their children's health-related quality of life (HRQOL) and behavior. METHOD: A cross-sectional study was conducted on 255 mother-child pairs (130 boys and 125 girls, mean age 8.4 years) from low-income Chinese families. We asked the mothers to self-report any doctor-diagnosed chronic diseases, and evaluate their children's HRQOL and behaviors with the Child Health Questionnaire-Parent Form-50 (CHQ-PF50) and the Strengths and Difficulties Questionnaire (SDQ), respectively. Multiple linear regression analysis was conducted to assess the independent spillover effect of maternal chronic disease on children's HRQOL and behaviors, with adjustment for confounders. The differential impact of maternal physical and mental diseases was also investigated. RESULTS: Over one-third of mothers (n = 88, 34.5%) reported one or more doctor-diagnosed chronic diseases. Multiple linear regression analysis showed that children of mothers with chronic diseases had significantly lower CHQ-PF50 scores in the parental impact-time, parental impact-emotional, and family activities subscales and psychosocial summary scores, as well as more hyperactive and inattentive problems measured by SDQ after adjustment for confounders. Maternal mental and physical disease showed a differential impact on children's HRQOL and behavior. CONCLUSIONS: Chronic disease in mothers might exert adverse effects on their children's HRQOL and behaviors. The effects could differ by maternal physical or mental disease status. Special attention and support should be paid to children of mothers with chronic disease as these children are at an increased risk of poor HRQOL and problematic behaviors.