The Cost-Effectiveness of Screening Primary Care Patients for Depression

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The summary below is from the full report titled "The Cost–Utility of Screening for Depression in Primary Care." It is in the 6 March 2001 issue of Annals of Internal Medicine (volume 134, pages 345-360). The authors are M Valenstein, S Vijan, JE Zeber, K Boehm, and A Buttar.

What is the problem and what is known about it so far?

Depression is an illness in which patients feel "down" and often lose interest in life. These feelings are sometimes an expected reaction to unfortunate life events; however, people may become depressed for no obvious reason. Feelings of depression can overwhelm people to the point where they lose their ability to carry out their usual activities. Depression is a very common problem, but it often goes undetected and untreated. Screening involves looking for depression in patients who see doctors for other reasons. Screening can improve the detection and, perhaps, treatment of depression. It is not known whether the costs of screening are worth its potential benefits, a concept known as cost-effectiveness.

Why did the researchers do this particular study?

To estimate the cost-effectiveness of screening primary care patients for depression. Primary care patients are patients being seen for general and preventive medical care.

Who was studied?

Rather than studying actual patients, the researchers used computers to simulate what would happen to a "virtual" group of 40-year-old primary care patients.

How was the study done?

The researchers used information from studies of actual patients to estimate what might happen if patients were not screened for depression at all, or if they were screened only one time, once every year, once every 3 years, or once every 5 years during primary care visits. They assumed that screening would involve having patients complete a written survey and that the doctor would ask patients questions about depression on the basis of their answers to the survey questions. Using a computer model, the researchers explored what would happen to patients over time, depending on whether they were screened for depression. They then calculated how much each strategy would cost for a given amount of benefit. The benefit was measured in units known as quality-adjusted life-years (QALY). This considers not only how long a person lives but also the quality of life during that time.

What did the researchers find?

Compared with no screening, screening primary care patients for depression one time would cost society $32,053 per QALY, screening once yearly would cost $192,444 per QALY, screening once every 3 years would cost $81,686 per QALY, and screening every 5 years would cost $50,988 per QALY. The cost-effectiveness of screening will improve if screening becomes less expensive and treatment of depression becomes more effective.

What were the limitations of the study?

This study was a computer simulation, so we cannot be sure what the results would be in actual patients.

What are the implications of the study?

Screening for depression more frequently than once every 5 years is more costly than most of the health care interventions that our society currently considers cost-effective.