Predicting the number of headache visits by type of patient seen in family practice.

OBJECTIVES: To examine the number of visits involving a headache diagnosis among patients to four family practice sites between July 1, 1995 and December 31, 1998.
BACKGROUND: Although the majority of care-seeking headache sufferers are seen in the primary care setting, few studies have attempted to document the relationship between type of headache as diagnosed by the family practice physician, and number of the patient's headache visits. Design.-Secondary analysis of administrative claims data.
METHODS: We compared headache visits per person-year by the age and sex of patient among patients classified according to headache diagnosis received: tension-type only; headache not otherwise specified (NOS) only; migraine only; tension-type and headache NOS; tension-type and migraine; headache NOS and migraine, and migraine, tension-type, and headache NOS. Patients with an International Classification of Diseases (version 9) code of 346 were considered to have a diagnosis of migraine, with 307.81 representing tension-type headache, and 784 representing headache NOS. Age was measured from date of birth to initial visit in the study period and patients were subdivided into 5-year age groups. Person-years "at risk" for each diagnosis was measured from the time of initial visit during the study period to December 31, 1998.
RESULTS: We examined data from 4112 patients who made 9322 visits with a headache diagnosis. We found that the average number of visits per person-year increases as the number of different types of headache diagnoses increased and were greatest for patients having migraine as opposed to headache NOS and tension-type diagnoses.
CONCLUSIONS: Headache type is an important predictor of the number of office visits involving a headache diagnosis in family practice. Patients with multiple headache diagnoses have more visits. Patients with combinations of headache diagnoses involving migraine are the most frequent visitors.