A tiered model of psychogeriatric service delivery: an evidence-based approach
Draper B, Brodaty H, Low LF;
Commented by , 24 Aug 2006
Background
The World Health Organisation consensus statement on the organisation of psychogeriatric services (1997) is clear that prevention and early intervention are necessary, alongside comprehensive assessment and management. Prevention is not happening in most areas, with primary and secondary care both expecting the other to do it – with nothing happening. This paper describes a tiered model for service planning and delivery.
Aims
To describe a tiered model for comprehensive evidence-based planning of service delivery for all mental disorders in late life.
Method
The authors adapted a previous tiered model they had developed for the management of the behavioural and psychological symptoms in dementia (BPSD) (ref. 1). Their model depicts 7 tiers in ascending order of severity and decreasing levels of prevalence, from the general population in Australia to the most extremely mentally ill older individuals (the model is pyramid shaped). For each tier they analysed the literature for evidence of efficacy of different interventions.
Results
Tier 1 – the lowest tier comprises the general population without mental disorder or risk factors for mental disorder (perhaps 85% of the older population). Health promotion interventions could theoretically keep most of the population in this tier by preventing development of, or delaying onset of, mental disorders by universal prevention strategies.
For example, cerebrovascular disease is implicated aetiologically in dementia, depression, mania and schizophrenia in late life: reduction in cerebrovascular risk factors in mid-life (stopping smoking, increasing exercise etc.) should reduce mental disorder in late life.
Tier 2 – individuals in this tier are healthy, but at high risk of developing new (or relapse of existing) mental disorder due to presence of risk factors. There is a reasonable evidence-base that selective prevention for high risk individuals (e.g., post stroke, or those with relapsing depression) is effective.
Tier 3 – Mild Mental Disorders – these disorders are very common in the general population, particularly depression and anxiety. Primary care workers and carer/consumer organisations provide most interventions, supported – often with education – by specialist mental health services. Several randomised controlled trials have demonstrated efficacy of psychoeducation of family caregivers of dementia patients in this tier.
Tier 4 – Moderate Mental Disorders – Patients have often had Tier 3 interventions that have not succeeded. Specialist intervention and collaboration between primary and secondary care is usually necessary.
Tier 5 – Moderate-Severe and Complex Mental Disorders – this tier is defined not just by symptom severity, but by the complexity of biopsychosocial co-morbidity, e.g., lack of family support, multiple physical illness. The authors postulate that such patients benefit from long term case management, though systematic evidence for this is lacking.
Tier 6 – Severe Mental Disorders – Patients often require institutionally based treatment and/or care. Examples include agitated/psychotic patients with delirium: patients with severe psychosis or depression, patients with chronic schizophrenia, and patients with severe BPSD. This group form the evidence-base for the need for acute psychogeriatric assessment units.
Tier 7 – Extreme Mental Disorders – Patients in this tier are rare, may have a forensic history, or may have a frontal lobe syndrome (e.g., fronto-temporal dementia) leading to disinhibited or dangerous behaviour. This patient group is neglected in the literature.
Dr Seymour's comments
Lack of space prevents more detail of the evidence-base for each tier of this descriptive study. Psychogeriatric services have traditionally paid little attention to tiers 1–3, as they have had to focus limited resources on tiers 4–6. However, there is an obvious logic in shifting the focus, if doing so prevents mental illness. A "mature" psychogeriatric service may be in a position to do this: less well developed services will necessarily have to focus on the most acutely ill and needy patients in crisis.
This model provides a clear framework to aid service planners and commissioners in developing psychogeriatric services, delineating the contributions of primary and secondary care, and shifting towards more prevention.
It is noteworthy and surprising that little research has been performed on tiers 6 and 7, one suspects for different reasons. Tier 6 comprises diverse patient groups; tier 7 comprises rare and unique cases that are difficult to randomise in trials.
References
1. Brodaty H, Draper BM, Low LF. Behavioural and psychological symptoms of dementia: a seven-tiered model of service delivery. Medical Journal of Australia 2003; 178 (5); 231-234