Cochrane reviews « Webwhispering

Are health checks good for you?

Posted by admin in Cancer, Cardiovascular disease prevention, Cochrane reviews, Disease-mongering, ICONS - Challenge on October 20th, 2012

It seems intuitive that it is a “good thing” to have regular health checks even if you are healthy. After all, you never know what beginnings of nasty diseases are lurking within you. Better detect these conditions early and so treat them early and perhaps save your life. Better to be safe than sorry. It is illegal not to have our cars MOT’d after all. And human beings are far more important than cars.

Hmmm……

A new Cochrane review published last week suggests otherwise.

GENERAL HEALTH CHECKS FOR REDUCING ILLNESS AND MORTALITY -FULL DATA

SHORTER VERSION

COUNTRY : INTERNATIONAL

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.

General health checks of people who are not complaining of disease is fashionable in many countries.

Even if useful, and this study suggests they are not, it is worth remembering that they make a lot of money for some and less money of others by keeping them employed. Are these good enough reasons for routine health checks (that may be associated with harms) on normal people?

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Mammography screening for breast cancer

Posted by admin in Breast cancer, Cochrane reviews, ICONS - Stethescope and apple, Mammography on March 10th, 2011

stethescopeapple

It seems sensible that women invited to attend for breast screening mammography take up the offer. You would imagine it would benefit not only themselves but their families and those close to them too and seems the sort of responsible thing all the neighbours and work colleagues would do also. Consequently it would be easy for the woman who did not attend to be regarded as being neglectful of herself or alternatively that she was a bit disorganised. She might be made to feel guilty.

After all, the sooner breast cancer is detected, the easier it is to treat.

Oh, it was that easy!

There is a lot of controversy around the benefits and harms of breast screening and it is likely it will remain a controversial issue for some time yet.

There is a Cochrane review on mammography. The link below links to a brief extract:

SCREENING FOR BREAST CANCER WITH MAMMOGRAPHY – BRIEF ABSTRACT

COUNTRY : DENMARK

“Screening for breast cancer with mammography

Screening with mammography uses X-ray to try to find breast cancer before a lump can be felt. The goal is to treat cancer early, when a cure is more likely. The review includes seven trials that involved 600,000 women who were randomly assigned to receive screening mammograms or not. The review found that screening for breast cancer likely reduces breast cancer mortality, but the magnitude of the effect is uncertain. Screening will also result in some women getting a cancer diagnosis even though their cancer would not have led to death or sickness. Currently, it is not possible to tell which women these are, and they are therefore likely to have breasts or lumps removed and to receive radiotherapy unnecessarily. The review estimated that screening leads to a reduction in breast cancer mortality of 15% and to 30% overdiagnosis and overtreatment. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged. In addition, 10 healthy women, who would not have been diagnosed if there had not been screening, will be diagnosed as breast cancer patients and will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings.

It is thus not clear whether screening does more good than harm. Women invited to screening should be fully informed of both the benefits and harms. To help ensure that the requirements for informed consent for women contemplating whether or not to attend a screening program can be met, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk.”

The link below is to more comprehensive information produced as a Cochrane Review. It can be downloaded as a PDF:

SCREENING FOR BREAST CANCER WITH MAMMOGRAPHY -A REVIEW

COUNTRY : DENMARK

“Eight eligible trials were identified. We excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87).

We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).

Numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42) for the two adequately randomised trials that measured this outcome; the use of radiotherapy was similarly increased.

This leaflet on the link below raises important questions and is intended to help women decide whether or not to have routine mammography.

INFORMATION LEAFLET – SCREENING FOR BREAST CANCER WITH MAMMOGRAPHY

COUNTRY : DENMARK