The Effects of Childhood Adversity on Perinatal Outcomes and Health Outcomes in the Subsequent Generation: A Cohort Study of Maternal and Child Health Service Use (I-CALM)

This is a single institution, longitudinal birth cohort. The previously approved Childhood Adversity and Lifetime Morbidity (CALM; ACTRN12622000870752) study linked participants from the Mater-University of Queens Study of Pregnancy (MUSP) to administrative health data. The original MUSP cohort study (n=7,214) followed children born at the Mater Mothers Hospital in Brisbane between the years of 1981 and 1983 through several follow up studies. The CALM study administratively linked Queensland Hospital Admitted Patient Data Collection (QHAPDC), Emergency Data Collection (EDC) data, and Consumer Integrated Mental Health and Addiction (CIMHA) data to the original MUSP cohort, resulting in a dataset with MUSP baseline variables and administrative health data for all children of the original mothers up to 40 years old (n=6,089). The I-CALM study will expand on the CALM study by: a) investigating the obstetric history of the MUSP birth cohort and the perinatal history of their children using the Perinatal Data Collection (PDC); and b) linking children’s perinatal records to their ED presentations, mental health service use, and hospital admissions in the same way as we did with their mothers (all data from the year of inception to 31 December 2023). The resulting dataset will therefore include health service use information for both the 1st and 2nd generations of the CALM cohort (children and grandchildren of the original mothers, respectively), as well as the original MUSP data. Use of administrative health data will address the problem of attrition in the birth cohort such that only 34%,were followed up at 30-year follow up for which the major factor was the inability to locate respondents (e.g., changes of address and phone number). Data linkage will be carried out by Data Linkage Queensland (DLQ) of the Statistical Services Branch of Queensland Health in exactly the same way as that approved by HREC for the previous CALM study but extended to include the PDC and the health records of their offspring (HREC/2022/QMS/83690). Data custodians for each database (MUSP, QHAPDC, CIHMA, EDC and PDC) will provide patient identifiers (name, date of birth and sex) stripped of any other information to DLQ. DLQ will import, clean, and standardise identifiable information for linkage. They will then produce an anonymised project-specific linkage key that is the most efficient and appropriate method for linking the desired cohort to the requested databases. After quality assurance is undertaken, the methodology used and any data issues will be summarised in a report, along with output variable descriptions and details of what is contained in the output file (typically provided as a .csv file). The final anonymised output file and report will then be provided to appropriate members of the research team using a secure method of transmission. No patient identifiers will be provided to the research team. Data will be obtained via Public Health Act (PHA) application as we are seeking to access linked administrative health data that is potentially re-identifiable and for which we are unable to obtain individual participant consent. In the first instance, we will seek approval from the data custodians for each of QHAPDC, PDC, EDC, CIHMA (Queensland statistical services branch; dlq@health.qld.gov.au), and MUSP (Jake Najman; j.najman@uq.edu.au) to ensure there are sufficient resources available within their departments to perform data extraction. DLQ will perform data linkage in collaboration with the data custodians for the abovementioned datasets. Cohort scope: All PCD data from inception to 31 December 2023 for generation one of MUSP (children of the original mothers), and all episodes of care from the EDC, CIHMA, and QHAPDC between inception and 31 December 2023 for generation two of MUSP (grandchildren of the original mothers). PDC variables: all variables related to obstetrics and perinatal data from inception (1st July 2004) to 31 December 2023 for both generation one and 2 of the MUSP cohort. EDC variables: all presentations to the ED for generation two of the MUSP cohort, including date and time of presentation, and ICD-10-AM codes from inception (from 1st July 2008) to 31 December 2023. QHAPDC variables: all hospital admissions for generation two of the MUSP cohort, including date and time of hospitalisation, number of nights stayed, and ICD-10-AM codes (including primary and secondary codes) from inception (1st January 2000) to 31 December 2023. CIHMA variables: using the SSB Master Linkage File, we will identify whether individuals have a CIHMA record or not, from inception (1st January 2010) to 31st December 2023.