Cohort profile: CROSS-TRACKS: a population-based open cohort across healthcare sectors in Denmark

Abstract

PurposeThis paper describes the open cohort CROSS-TRACKS, which comprises population-based data from primary care, secondary care and national registries to study patient pathways and transitions across sectors while adjusting for sociodemographic characteristics.ParticipantsA total of 221 283 individuals resided in the four Danish municipalities that constituted the catchment area of Horsens Regional Hospital in 2012–2018. A total of 96% of the population used primary care, 35% received at least one transfer payment and 66% was in contact with a hospital at least once in the period. Additional clinical information is available for hospital contacts (eg, alcohol intake, smoking status, body mass index and blood pressure). A total of 23% (n=8191) of individuals aged ≥65 years had at least one potentially preventable hospital admission, and 73% (n=5941) of these individuals had more than one.Findings to dateThe cohort is currently used for research projects in epidemiology and artificial intelligence. These projects comprise a prediction model for potentially preventable hospital admissions, a clinical decision support system based on artificial intelligence, prevention of medication errors in the transition between sectors, health behaviour and sociodemographic characteristics of men and women prior to fertility treatment, and a recently published study applying machine learning methods for early detection of sepsis.Future plansThe CROSS-TRACKS cohort will be expanded to comprise the entire Central Denmark Region consisting of 1.3 million residents. The cohort can provide new knowledge on how to best organise interventions across healthcare sectors and prevent potentially preventable hospital admissions. Such knowledge would benefit both the individual citizen and society as a whole.

Healthcare Use in the Five Years Before a First Infertility Diagnosis: A Danish Register-Based Case–Control Study in the CROSS-TRACKS Cohort

“…We conducted a nested case–control study in the CROSS-TRACKS Cohort 17 with incidence density sampling design. We linked health information across national registries available in the CROSS-TRACKS Cohort by using the unique personal identification number assigned to all Danish citizens at birth or after immigration.…”

“…Information on the participants, including civil status, and register data on their healthcare use was available from the population-based open CROSS-TRACKS Cohort, which has been described in detail elsewhere. 17 In the CROSS-TRACKS Cohort, individuals were included on their 18th birthday or when moving into the catchment area of Horsens Regional Hospital (Horsens, Odder, Skanderborg and Hedensted municipalities). Individuals were followed from the date of inclusion until the end of the study period or date of death.…”

“…23 In the CROSS-TRACK Cohort, the NPR data were available from 1 September 2002. 17 First, we included cases on the basis of the primary infertility diagnosis (DN97 spectrum diagnoses). Second, we also identified cases as women with a secondary infertility diagnosis if the women had a relevant primary diagnosis of reproductive diseases (endometriosis, PCOS, or ovarian insufficiency) related to the same fertility contact.…”

“…The NPR does not contain information from non-refundable contacts with private psychologists, which account for a minor subset of contacts. 17 …”

The Framing of machine learning risk prediction models illustrated by evaluation of sepsis in general wards

“…The dataset used in this study came from the CROSS-TRACKS cohort, a population-based, open cohort, containing routinely collected data from primary and secondary healthcare partners, combined with data from national registries. A full description of the cohort has been published [30], but, in brief, the CROSS-TRACKS cohort consists of all citizens aged 18+ residing in the catchment area of Horsens Regional Hospital, a teaching hospital in the Central Denmark region, which serves a population of 221,283 residents in four Danish municipalities (Odder, Hedensted, Skanderborg, and Horsens). The cohort entry date was September, 1 2012, and inclusion will last through 2022.…”