Epidemiology of Incarceration: Characterizing Jail Incarceration for Public Health Research

Background: Each year, 9 million individuals cycle in and out of jails. The under-characterization of incarceration as an exposure poses substantial challenges to understanding how varying levels of exposure to jail may affect health. Thus, we characterized levels of jail incarceration including recidivism, number of incarcerations, total and average number of days incarcerated, and time to reincarceration. Methods: We created a cohort of 75,203 individuals incarcerated at the Coconino County Detention Facility in Flagstaff, Arizona, from 2001 to 2018 from jail intake and release records. Results: The median number of incarcerations during the study period was one (interquartile range [IQR] = 1-2). Forty percent of individuals had >1 incarceration. The median length of stay for first observed incarcerations was 1 day (IQR = 0-5). The median total days incarcerated was 3 (IQR = 1-23). Average length of stay increased by number of incarcerations. By 18 months, 27% of our sample had been reincarcerated. Conclusion: Characteristics of jail incarceration have been largely left out of public health research. A better understanding of jail incarcerations can help design analyses to assess health outcomes of individuals incarcerated in jail. Our study is an early step in shaping an understanding of jail incarceration as an exposure for future epidemiologic research. See video abstract at, http://links.lww.com/EDE/B536.