The assertive intervention for deliberate self harm (AID) trial was designed as a pragmatic, randomised, parallel group, superiority trial with blinded outcome assessment. The trial protocol was approved by the local ethics committee (journal number KF-01 271146), the Danish Data Protection Agency (journal number 2011-41-6398), and registered at clinicalTrials.gov (identifier NCT00700089). It was undertaken at a single location at the Copenhagen University Hospital, Copenhagen, Denmark.
Participants were patients admitted after a suicide attempt to acute emergency units, intensive care units, paediatric units, and psychiatric emergency rooms in six regional hospitals in the catchment area of Copenhagen. We made referral agreements through personal meetings with units in charge of standard treatment provided to patients with suicide attempts. We distributed pocket sized laminated sheets with inclusion and exclusion criteria to doctors in somatic and psychiatric units. Children and adolescents were referred to the AID trial from the hospital conducting the trial and from other hospitals treating children, in addition to standard procedures for psychiatric consultation. General practitioners who contacted hospitals to refer possible patients with recent suicide attempt were also informed about the trial.
We included male and female patients aged 12 years and older with a suicide attempt within the past 14 days who were able to read and understand the informed consent statement. We made one exception with regard to the age criteria; a female patient was included shortly before her twelfth birthday.
All the suicide attempts of included patients fulfilled the WHO definition: “An act with a non-fatal outcome, in which an individual deliberately initiates a non-habitual behaviour that without intervention from others will cause self harm, or deliberately ingests a substance in excess of the prescribed or generally recognized therapeutic dosage, and which is aimed at realizing changes which the subject desired via the actual or expected physical consequences.”28
Patients presenting with self injuries, such as cutting, were only included if they also met the definition of non-habitual behaviour. This was verified for each single case through patients’ self reports and medical records. Patients diagnosed with severe personality disorders, including eating disorders, were invited to join the study, as were patients with alcohol misuse or with no offer of subacute treatment meeting the need for suicide prevention.
We excluded patients admitted to a psychiatric ward for more than 14 days after the index attempt. This enabled us to investigate the effect of the intervention for high risk patients in subacute phases. We also excluded patients who had been diagnosed with schizophrenia spectrum disorders (ICD-10: F20-29), severe depression (ICD-10: F32.2, F32.3, F33.2, and F33.3.), severe bipolar disorder (ICD 10: F30 and F31), and severe dementia (ICD 10: F0-9), because intensive outreach teams are already implemented as standard care for these patients in Denmark. Furthermore, patients with severe depression or bipolar disorder and suicidal behaviour would probably need inpatient care and would not be eligible for outpatient treatment. We also excluded patients who were receiving outreach services from social service agencies or living in institutions, to prevent mixing different effects and avoid confounders.29
The standard treatment consisted of referral to a range of different treatment modalities, dependent on the diagnosis and the clinical and social conditions of the patient. While the patient was still being treated for the self injury, a routine psychiatric evaluation would often be used to determine whether he or she should be referred for further treatment—for example, general practitioner, psychological therapy, or treatment for alcohol abuse. In the standard treatment there was no procedure to ensure compliance with the recommended treatment. For the most part, the patients were responsible for contacting the treatment provider to which they were referred. As a part of the standard treatment, the Centre of Excellence in Suicide Prevention Copenhagen offered six to eight therapeutic sessions to patients who did not abuse substances and were not receiving other ongoing treatments. A psychologist provided these sessions as short term therapy with risk assessment tools from the Collaborative Assessment and Management of Suicidality (CAMS) approach.30
This option of after-treatment was available to patients in both groups. Pharmacological treatment of any kind was continued or prescribed in both groups when relevant.
The AID intervention was provided as case management with crisis intervention and flexible, problem solving, assertive outreach through motivational support and actively assisting patients to and from scheduled appointments, to improve compliance with after-treatment. The intervention represented eight to 20 flexible outreach consultations performed by specialised nurses (AID managers) over 6 months in addition to standard treatment. The first consultation was offered a few days after discharge and focused on acute prevention strategies, such as developing a crisis intervention plan in case of relapse. Subsequent consultations established a professional relationship, addressed problem solving strategies, and undertook specific actions. To ensure continuity, the same AID manager contacted the patient throughout the 6 months of the intervention. Motivation towards after-treatment was stressed as a core feature and referral was organised. Consultations were provided equally as home visits or meetings in cafes, as preferred, as well as meetings with healthcare, official, and social services to accommodate individual needs. The AID manager was responsible for maintaining contact, but the patient was asked to make contact between consultations if necessary. Telephone calls and text messages were frequently used to strengthen the alliance. The manager offered mediating family consultations to adolescents and their relatives, and suggested the involvement of social or professional networks irrespective of age. During relapse or stressful life events, frequency of contact was intensified, including availability of contact out usual hours to prevent subsequent suicidal behaviour. If the patient had severe suicidal impulses, the manager asked him or her to take a prepaid taxi to the psychiatric emergency room if all other items on the crisis intervention plan had failed in changing the impulses or providing relief of psychic pain. A minimum of four personal contacts was defined as adherence to the AID intervention; additional phone calls and text messages were not defined. Cafe visits did not count as crisis interventions. If, however, the patient revealed severe suicidal impulses during a cafe visit, the manager would usually prolong contact to cover decisions of crisis management.
The intervention staff (AID managers) were highly qualified psychiatric nurses with specialised training in suicidology. Regular consultations were done with the supervising chief psychiatrist and research assistant to ensure adherence to the research protocol. The target for maximum caseload for each AID manager was 20 patients in active intervention treatment at any time. If a patient died by suicide, the AID manager assigned the patient would immediately be relieved from duty for a period of time.
We interviewed patients at baseline to obtain information on socio-demographic variables and method used for the index suicide attempt. The outcomes of interest were repeated suicide attempt and death by suicide with a follow-up period of one year after inclusion date. We obtained information on these events through ICD-10 diagnoses (recorded as part of standardised hospital registration procedure) and review of medical records. Additionally, we collected self reported data on events within the first year of follow-up, through telephone interviews with patients. Patients who could not be reached by phone after persistent attempts were contacted by regular mail.
An external medical evaluation committee conducted a blinded outcome assessment using medical records. Owing to the nature of the study design, the intervention staff were not blinded. The researcher conducting the analyses on self reported outcomes was also not blinded.
On the basis of previous studies,27
we estimated an expected repetition risk of 30% in the standard group and 15% in the intervention group within one year of the index attempt. With an α value of 0.05, we required 120 patients randomised to each treatment arm to reach a power of 80%.32
Computer randomisation was done by an independent research assistant at the Mental Health Centre Copenhagen, stratified by whether the patient had previously attempted suicide (first attempt v previous attempt), previous psychiatric contacts or hospitalisation (none v previous contacts), and alcohol consumption at time of suicide attempt (none v alcohol consumption). The AID managers were informed of the allocation by phone and the patients were immediately informed of the outcome. The randomisation procedure ensured adequate sequence generation and allocation concealment.
Statistics and data analysis
We assessed frequencies, means, and standard deviations of socio-demographic and patient characteristics and tested differences between groups with χ2 or independent sample t tests. We calculated the log odds of a patient having a recorded or self reported new suicide attempt in the 12 months following the index attempt. In subsequent planned analyses, we adjusted for possible baseline differences relevant for the primary outcome. All patients were included in the analysis regardless of subsequent adherence to treatment, according to the intention to treat principle. All statistical tests were two sided and P values less than 0.05 were considered statistically significant. We imputed missing values for the self reported outcome as a dependent variable using multiple imputations by applying a linear regression model with the following predictor variables: allocation, suicide attempt prior to index attempt, alcohol intoxication at index attempt, psychiatric contact prior to index attempt, unemployment, antidepressant medication, and discharge from a psychiatric hospital within the previous four weeks. The imputation was conducted using 100 imputations and 20 iterations. The pooled estimates from these imputations were subsequently used for analysis. The statistical software package SPSS version 19.0 was used for the analyses.
We obtained written consent from all participants after providing them with both oral and written information about the conditions of participating in scientific research in general and with specific details of the AID trial. Age specific consent forms were developed for children and adolescents. Written consent from both custody holders was required and obtained for children aged 11-14 years. Adolescents aged 15-17 years were allowed to decide and give written consent themselves as long as their parents were informed, according to the Danish Committee on Biomedical Research Ethics.