Homelessness and police-recorded crime victimisation: a nationwide, register-based cohort study

Abstract

Background: Homelessness is associated with crime victimisation, which is a leading cause of death, exacerbates health problems, and increases the risk of violence. We aimed to study the risk of police-recorded crime victimisation in individuals with experiences of homelessness compared with the general population.

Methods: We did a nationwide, register-based cohort study of people aged 15 years or older, who were alive in 2001 and born in Denmark between 1980 and 2001. The cohort was constructed using the Danish Civil Registration System, with data linked across other registries (including the Danish Homeless Register, Danish Psychiatric Central Research Register, and the Danish Central Crime Register) by use of personal identification numbers. The exposure, experience of homelessness, was defined as at least one contact with a homeless shelter. The outcome was the date of first police-recorded crime victimisation. We calculated incidence rates per 1000 person-years, incidence rate ratios (IRRs), and cumulative probability of any crime victimisation and of violent crime victimisation. Psychiatric disorders, socioeconomic markers, and history of criminal offences were included as confounders.

Findings: Within the study period (Jan 1, 2001, to Dec 31, 2015), 1 182 749 individuals (9 831 776 person-years) aged 15-35 years were included, of which 184 813 (15·6%) had at least one crime victimisation incident (73 999 [40%] of which were violent victimisations). 4286 individuals (22 240 person-years) had at least one homeless shelter contact. Relative to the general population, and adjusting for age and calendar year, individuals with experience of homelessness had an increased risk of any crime victimisation (IRR 2·7 [95% CI 2·4-3·0]) in females and 2·3 [2·1-2·5] in males), and especially of violent crime victimisation (7·2 [6·3-8·2] in females and 3·6 [3·2-4·0] in males). This increased risk remained significant after further adjustments for potential confounders. People with both a psychiatric diagnosis and experience of homelessness had the highest risk of violent victimisation (IRR 10·1 [95% CI 8·6-11·9] in females and 4·3 [3·8-4·9] in males), while people with no psychiatric diagnosis or experience of homelessness (the reference group) had the lowest risk. In the 5 years after an individual's first homeless shelter contact, the cumulative probabilities of any crime victimisation were 23% (95% CI 21-26) in females and 16% (15-18) in males, which were substantially higher than those of the general population.

Interpretation: Homeless populations are at substantially increased risk of crime victimisation, highlighting the need for strategic and targeted approaches to prevent homelessness and to help people out of homelessness. Improvements in multiagency working (such as between homeless shelters, health-care services, substance misuse services, and police forces) might be important to reduce the risk of victimisation in marginalised populations, such as those with complex psychiatric or social problems, with experience of homelessness.

Funding: Lundbeck Foundation.

Figure 1. Combined effects of experience of homelessness and psychiatric disorders, including substance use disorders, on risk of violent police-recorded crime victimisation

Incidence rate ratios for violent police-recorded crime victimisation in females (A) and males (B) by homelessness experience and psychiatric disorder. The reference group was individuals with no experience of homelessness during the study period (2001–15) and no psychiatric contact. Model 1 is adjusted for age and calendar year. Model 3 is adjusted for age, calendar year, highest parental educational level at the year of the cohort member’s 15th birthday, and their father’s status (known vs unknown). Error bars are 95% CIs.

Figure 2. Cumulative probability of any police-recorded crime victimisation (A) and violent police-recorded crime victimisation (B) in 5 years after first homeless shelter contact

Probability of victimisation within 5 years is shown for individuals with homeless shelter contact and for age-matched and sex-matched controls from the general population. Because of rounding differences, the number of person-years summed up for each covariate can be different from the total number of person-years. *Determined for the year of the cohort member’s 15th birthday. †Defined as a hierarchical covariate with the following hierarchy: substance use disorder; schizophrenia or bipolar disorder; depressive, anxiety, or stress-related disorder; and any other mental illness.