The effect of comorbid chronic diseases on primary healthcare use of cancer patients.

Purpose: More than two-thirds of cancer patients have one or more chronic diseases besides cancer. We studied the effect of specific diseases on primary healthcare use to examine the possible synergistic effect of cancer and chronic diseases on healthcare utilisation. Methods: Using data from the NIVEL Primary Care Database, we determined the number of general practitioner (GP) contacts 2–5 years after the diagnosis of cancer in relation to the number of comorbid chronic diseases and for five different groups: cancer patients with (1) diabetes mellitus, (2) coronary artery disease (CAD), (3) osteoarthritis, (4) COPD and (5) no chronic disease. For each patient we selected two non-cancer controls from the same GP practice with the same chronic disease, age and sex. Results: We included 3502 cancer patients and 6838 non-cancer controls. The proportion with more than one chronic disease was lowest in patients with diabetes mellitus (65%) and highest in patients with CAD (77%). Cancer patients without a chronic disease had on average 6.5 GP contacts per year, those with a comorbid disease almost twice as many (ranging from 10 for osteoarthritis to 12.4 for COPD). A similar difference was seen in non-cancer controls. The number of GP contacts increased with the number of chronic diseases, up to on average 17 per year in cancer patients with COPD and 4 for other diseases. No differences between cancer patients and controls were found if primary healthcare use was stratified by number of chronic diseases, and cancer was counted as a chronic disease. Conclusion: Two to five years after diagnosis, cancer seems to have the same effect on primary healthcare use as having a chronic disease. GPs could learn from the approach they are currently using for chronic diseases and develop primary care pathways for cancer as well.