RIO GRANDE, P.R. — Primary care physicians don't appear to treat depression any more aggressively in patients who have medical comorbidities, compared with other patients, despite mounting evidence showing that depression may worsen medical outcomes.
The conclusions were based on a review of more than 20,000 adult records. “There is good evidence that the rate of depression is higher in persons with certain medical comorbidities,” Dr. James Gill said at the annual meeting of the North American Primary Care Research Group. “You could make the argument that persons with depression should be treated more aggressively if they have comorbid conditions,” he added.
In a previous study, Dr. Gill, president of Delaware Valley Outcomes Research LLC, reviewed a large database of patients treated by a range of medical specialists and found no significant differences among the specialists in terms of their use of antidepressant medications to treat depressed patients with and without medical comorbidities (Int. J. Psychiatry 2008;38:203–15).
In order to focus on primary care physicians specifically, Dr. Gill conducted a secondary analysis of 209 family medicine and general internal medicine physicians and 24,876 of their patients, aged 18 years and older, who had diagnoses of depression.
The study population included 1,849 patients with incident depression diagnosed during the 1-year period from October 2006 through October 2007. Study participants had at least one office visit during the year and an active diagnosis of depression as of the end of the year. Data were collected from electronic medical records via the Medical Quality Improvement Consortium.
Approximately 75% of the patients were on any type of antidepressant medication at the study's end. A total of 92% were taking at least the minimum dosage of their prescribed medications, and almost half (49%) were taking the full dosage.
In addition, about one-quarter of the patients in the study had at least one of the six medical comorbidities included in the review: coronary heart disease, heart failure, cerebrovascular disease, chronic obstructive pulmonary disease, cancer, and diabetes. The most common comorbidity was diabetes, affecting 13%.
After the researchers controlled for age, gender, and additional comorbidities, none of the six comorbidities were a significant predictor of any antidepressant medication use or of the dosage. Nor did the researchers find any significant differences in medication use by comorbidity in a subanalysis for the patients with incident depression during the observation year.
Patients with comorbid conditions were slightly more likely to be taking the maximum dosage of an antidepressant, and patients with medical comorbidities in the incident group were slightly less likely to be on medications.
Primary care providers may not be treating depression aggresively due to concerns about medication side effects and the cost of additional medications. The study was limited by a lack of information about the severity of the patients' depression, Dr. Gill said.
But the question remains as to whether treating depression more aggressively can improve the comorbidities, he added, and more research is needed to explore this topic.
Dr. Gill had no financial conflicts to disclose.