Variability in vulnerability assessment of older people by individual general practitioners: a cross-sectional study.

Background: In clinical practice, GPs appeared to have an internalized concept of "vulnerability." This study investigates the variability between general practitioners (GPs) in their vulnerability-assessment of older persons.
Methods: Seventy-seven GPs categorized their 75-plus patients (n = 11392) into non-vulnerable, possibly vulnerable, and vulnerable patients. GPs personal and practice characteristics were collected. From a sample of 2828 patients the following domains were recorded: sociodemographic, functional [instrumental activities in daily living (IADL), basic activities in daily living (BADL)], somatic (number of diseases, polypharmacy), psychological (Mini-Mental State Examination, 15-item Geriatric Depression Scale; GDS-15) and social (De Jong-Gierveld Loneliness Scale; DJG). Variability in GPs' assessment of vulnerability was tested with mixed effects logistic regression. P-values for variability (pvar) were calculated by the log-likelihood ratio test.
Results: Participating GPs assessed the vulnerability of 10,361 patients. The median percentage of vulnerable patients was 32.0% (IQR 19.5 to 40.1%). From the somatic and psychological domains, GPs uniformly took into account the patient characteristics 'total number of diseases' (OR 1.7, 90% range  = 0, p var = 1), 'polypharmacy' (OR 2.3, 90% range  = 0, p var = 1) and 'GDS-15' (OR 1.6, 90% range  = 0, p var = 1). GPs vary in the way they assessed their patients' vulnerability in the functional domain (IADL: median OR 2.8, 90% range 1.6, p var < 0.001, BADL: median OR 2.4, 90% range 2.9, p var < 0.001) and the social domain (DJG: median OR 1.2, 90% range  = 1.2, p var < 0.001).
Conclusions: GPs seem to share a medical concept of vulnerability, since they take somatic and psychological characteristics uniformly into account in the vulnerability-assessment of older persons. In the functional and social domains, however, variability was found. Vulnerability assessment by GPs might be a promising instrument to select older people for geriatric care if more uniformity could be achieved.
Trial Registration: Netherlands Trial Register NTR1946.