Study design of the Routine Outcome Monitoring for Geriatric Psychiatry & Science (ROM-GPS) project; a cohort study of older patients with affective disorders referred for specialised geriatric mental health care.

BACKGROUND: Affective disorders, encompassing depressive-, anxiety-, and somatic symptom disorders, are the most prevalent mental disorders in later life. Treatment protocols and guidelines largely rely on evidence from RCTs conducted in younger age samples and ignore comorbidity between these disorders. Moreover, studies in geriatric psychiatry are often limited to the "younger old" and rarely include the most frail. Therefore, the effectiveness of treatment in routine clinical care for older patients and impact of ageing characteristics is largely unknown. OBJECTIVE: The primary aim of the Routine Outcome Monitoring for Geriatric Psychiatry & Science (ROM-GPS) - project is to examine the impact of ageing characteristics on the effectiveness of treatment for affective disorders in specialised geriatric mental health care. METHODS: ROM-GPS is a two-stage, multicentre project. In stage one, all patients aged >/=60 years referred to participating outpatient clinics for specialised geriatric mental health care will be routinely screened with a semi-structured psychiatric interview, the Mini International Neuropsychiatric Interview and self-report symptom severity scales assessing depression, generalized anxiety, hypochondria, and alcohol use. Patients with a unipolar depressive, anxiety or somatic symptom disorder will be asked informed consent to participate in a second (research) stage to be extensively phenotyped at baseline and closely monitored during their first year of treatment with remission at one-year follow-up as the primary outcome parameter. In addition to a large test battery of potential confounders, specific attention is paid to cognitive functioning (including computerized tests with the Cogstate test battery as well as paper and pencil tests) and physical functioning (including multimorbidity, polypharmacy, and different frailty indicators). The study is designed as an ongoing project, enabling minor adaptations once a year (change of instruments). DISCUSSION: Although effectiveness studies using observational data can easily be biased, potential selection bias can be quantified and potentially corrected (e.g. by propensity scoring). Knowledge of age-related determinants of treatment effectiveness, may stimulate the development of new interventions. Moreover, studying late-life depressive, anxiety and somatic symptom disorders jointly enables data-driven studies for more optimal classification of these disorders in later life. TRIAL REGISTRATION: Dutch Trial Register: NL6704 ( www.trialregister.nl ). Retrospectively registered on 2017-12-05