The inter-contact interval: a new measure to define frequent attenders in primary care

Frequent attenders receive much attention in primary care research. Defining frequent attendance is crucial for an adequate view on this group of demanding patients. We aimed to develop a purely contact-based definition of "frequent attendance" and to apply it to real patients.

From electronic records of 123 general practices in Germany, patients' inter-contact intervals (ICI) between two consecutive doctor-patient-contacts were calculated in this retrospective observational study. ICI less than 7 days were labelled "frequent attendance", patients with 60% or more of such intervals "frequent attenders (new view)". In contrast, patients having at least 24 contacts per calendar year were considered "frequent attenders (traditional view)". Both groups were analysed in their diseases and demands, using multiple logistic regression.

A total of 177,057 patients with at least 3 ICI in 1996 until 2006 yielded 4,408,033 ICI. One third were "short" ICI (less than 7 days), resulting in 19,759 (11.2%) frequent attenders (new). In contrast, 22,921 (12.9%) patients were frequent attenders (traditional). Compared to non-frequent attenders, frequent attenders (new) were more likely to have pneumonia (OR 1.66), stroke (OR 1.49), dementia (OR 1.46), or severe substance abuse (OR 1.44), also to need home visits or emergency attention. Frequent attenders (traditional) were more likely to have dementia (OR 2.76) or stroke (OR 2.06), and by far to need home visits (OR 5.43; all p < 0.001).

A new measure, the interval in days of two consecutive face-to-face contacts (ICI), widens our perspective on frequent attenders in general practice. In many cases, their consultation behaviour and need for medical services seem to follow "disease logic".