New Cochrane Review (2012): General health checks in adults for reducing morbidity and mortality from disease

General health checks involve multiple tests in a person who does not feel ill with the purpose of finding disease early, preventing
disease from developing, or providing reassurance. Health checks are a common element of health care in some countries. To many
people health checks intuitively make sense, but experience from screening programmes for individual diseases have shown that the
benefits may be smaller than expected and the harms greater. One possible harm from health checks is the diagnosis and treatment
of conditions that were not destined to cause symptoms or death. Their diagnosis will, therefore, be superfluous and carry the risk of
unnecessary treatment.

We identified 16 randomised trials which had compared a group of adults offered general health checks to a group not offered health
checks. Results were available from 14 trials, including 182,880 participants. Nine trials studied the risk of death and included 155,899
participants and 11,940 deaths. There was no effect on the risk of death, or on the risk of death due to cardiovascular diseases or cancer.
We did not find an effect on the risk of illness but one trial found an increased number of people identified with high blood pressure and
high cholesterol, and one trial found an increased number with chronic diseases. One trial reported the total number of new diagnoses
per participant and found a 20% increase over six years compared to the control group. No trials compared the total number of new
prescriptions but two out of four trials found an increased number of people using drugs for high blood pressure. Two out of four trials
found that health checks made people feel somewhat healthier, but this result is not reliable. We did not find that health checks had an
effect on the number of admissions to hospital, disability, worry, the number of referrals to specialists, additional visits to the physician,
or absence from work, but most of these outcomes were poorly studied. None of the trials reported on the number of follow-up tests
after positive screening results, or the amount of surgery used.

One reason for the apparent lack of effect may be that primary care physicians already identify and intervene when they suspect a
patient to be at high risk of developing disease when they see them for other reasons. Also, those at high risk of developing disease may
not attend general health checks when invited. Most of the trials were old, which makes the results less applicable to today’s settings
because the treatments used for conditions and risk factors have changed.
With the large number of participants and deaths included, the long follow-up periods used in the trials, and considering that death
from cardiovascular diseases and cancer were not reduced, general health checks are unlikely to be beneficial. 

Read the full Cochrane Review: General health checks in adults for reducing morbidity and mortality from disease