A new marker of primary care utilization - annual accumulated duration of time of visits.

Background: Most of the research on primary care workload has focused on the number of visits or the average duration of visits to a primary care physician (PCP) and their effect on the quality of medical care. However, the accumulated annual visit duration has yet to be examined. This measure could also have implications for the allocation of resources among health plans and across regions. In this study we aimed to define and characterize the concept of "Accumulated Annual Duration of Time" (AADT) spent with a PCP.  METHOD: A cross-sectional study based on a national random sample of 77,247 adults aged 20 and over. The study's variables included annual number of visits and AADT with a PCP, demographic characteristics and chronic diseases. The time period was the entire year of 2012.

Results: For patients older than 20 years, the average annual number of visits to a PCP was 8.8 ± 9.1, and the median 6 ± 10 IQR (Interquartile Range). The mean AADT was 65.8 ± 75.7 min, and the median AADT was 43 ± 75 IQR minutes. The main characteristics of patients with a higher annual number of visits and a higher AADT with a PCP were: female, older in age, a higher Charlson index and a low socio-economic status. Chronic diseases were also found to increase the number of annual visits to a PCP as well as the AADT, patients with chronic heart failure had highest AADT in comparison to others (23.1 ± 15.5 vs. 8.6 ± 8.9 visits; and 165.3 ± 128.8 vs. 64.5 ± 74 min). It was also found that the relationship between AADT and age was very similar to the relationship between visits and age.

Conclusion: While facing the ongoing increase in a PCP's work load and shortening of visit length, the concept of AADT provides a new measure to compare between different healthcare systems that allocate different time frames for a single primary care visit. For Israel, the analysis of the AADT data provides support for continued use of the number of visits in the capitation formula, as a reliable and readily-accessible indicator of primary care usage.