Objective: Dementia is a serious public health problem. General medical comorbidity is common in dementia patients and critical to their care. However, little is known about medical comorbidity in these patients, and there are no straightforward bedside global rating scales for the seriousness of comorbid medical illness. This paper describes the development and measurement properties of the General Medical Health Rating (GHMR), a rapid global rating scale of medical comorbidity in dementia patients.
Design: Interrater reliability, concurrent validity, and predictive validity of the GMHR are reported.
Setting: An outpatient dementia clinic, assisted living, and nursing home.
Participants: A total of 819 consecutive dementia clinic outpatients and 180 consecutive admissions to Copper Ridge, a long-term care residence for people with dementia, were included in the study.
Results: GMHR was found to be highly reliable (weighted kappa = .91). Across all stages and types of dementia, GMHR ratings were correlated with number of comorbid medical conditions, number of medications being taken for comorbid conditions, and with activity of daily living impairment, even after adjustment for severity of dementia. GMHR ratings were also a strong predictor of falls and of mortality in long-term care residents after adjustment for age and severity of dementia.
Conclusion: GMHR is a reliable, valid, global bedside measure of severity of general medical comorbidity for patients with dementia that can be used for clinical and research purposes.