The study was conducted at the two largest public psychiatric hospitals in Stockholm County (1.9 million inhabitants) serving 289,000 and 400,000 people, respectively. Both hospitals provide voluntary as well as involuntary care. Patients were recruited from the two general psychiatric wards at the first hospital and from seven general psychiatric wards at the second hospital (excluding a ward negative to research). Patients were also recruited from the emergency unit at the second hospital, which serves the entire Stockholm County. This unit admits any individual for acute psychiatric evaluation and treatment. Prior psychiatric contact or referral by a third party is not required. The clinician may decide to admit the patient, to let the patient stay over night for observation, or to advise the person to return home.
Health care in Sweden, of any kind, is provided at a low cost to the individual who instead pays through general taxation. The private sector in psychiatry was, at the time of the study, small and of marginal importance. Treatment of patients with psychoactive substance dependence disorders in Stockholm County is run by a separate organisation, albeit co-morbidity is often seen in general psychiatry.
Psychiatric patients eligible for the study were between 18 and 60 years of age and returning home after an acute consultation or admission at any of the two hospitals and had a Swedish social security number (needed for access to records and national registers) and had a clinical ICD diagnosis [26
] and had capacity to pursue an interview in Swedish or English. We chose to use the clinical diagnoses rather than conduct a specific diagnostic research interview, for two reasons; the exact diagnosis was not a main focus of the study and an extension of the research interview might have jeopardised the response rate and data quality.
Approximately 512 patients from the inpatient units of the two hospitals and 463 patients from the psychiatric emergency unit were eligible for the study. Thus, approximately 975 patients were eligible, 497 were approached (50%) and 390 patients accepted to participate (78% of all approached). Those who were not approached had left the hospital at a time when the research assistant was off duty (evenings, nights, weekends and holidays), and therefore no information about the non-approached patients could be retrieved. There were no significant difference between participants and refusals in terms of gender, age, diagnosis, admitted/not admitted, length of admission, voluntary/involuntary care, and which hospital was concerned (Table ).
Victimisation among psychiatric patients in Stockholm: socio-demographic and clinical characteristics of cases, controls and refusals
The controls were selected from the annual surveys of living conditions (ULF), conducted by Statistics Sweden [21
], which interviews, in person, a representative sample of 6,000 people from the general population. The attrition rate between 2003 and 2006 was 24%. The inclusion criteria of the subjects of the survey are the same as those of the cases except that the survey includes people without a Swedish social security number. The survey covers many aspects of the participants’ living conditions, including two specific questions pertaining to experiences of having been victimised.
The controls were selected in a two-step procedure. First, all residents of Stockholm County, interviewed by the ULF survey in the period 2003 through 2006, were identified. Secondly, three controls per case, matched in terms of gender and age, were randomly drawn from this group, resulting in 1,170 controls.
Patients were interviewed from 10 January to 12 December 2007 by two external and independent research assistants. When staff announced that a patient was returning home, he/she was asked to participate (after controlling eligibility). No compensation was offered. A structured 10–15 min interview was conducted after discharge by the responsible clinician but before the patient left the hospital building. The participants were assured that the information from the research interview would not be reported to the responsible clinician unless it concerned a threat towards a named person or a case of child mistreatment. The study was approved by Stockholm Regional Ethical Committee (Dnr 2006/1231-31).
Data on gender, age, voluntary/involuntary care, admission/not admission and duration of admission of the cases were collected from medical case records. The interview provided further information on socio-economic status, level of education and country of birth using questions from the ULF survey. Diagnosis according to ICD [26
] was obtained from the medical case records or via verbal communication with the responsible clinician.
The outcome variable, victimisation, was measured by asking the patients the same two questions as posed to the controls in the ULF survey: “have you been subjected to violence resulting in visible injuries during the last twelve months?” and “have you been subjected to violence that required medical attention during the last twelve months?” The latter type of victimisation is considered more severe than the former. Sexual violence is included, provided it left visible physical marks and/or required medical attention.
All data are presented in terms of descriptive statistics, i.e. mean and standard deviation for continuous data, and frequency and relative frequency for categorical data together with the exact (binominal distribution) 95% confidence intervals (CI). Participants and refusals were compared using t test for continuous data and Chi-square for categorical data. Data were checked for skewness. All tests were two-tailed and P < 0.05 was regarded as statistically significant. The crude odds ratios (OR) and the corresponding 95% CI of being violently victimised among the cases versus controls were computed using Stata version 10.1.