tisdag 18 oktober 2011

Hälsokontroller - värt det, ibland

Jag har skrivit om det tidigare, men det förtjänar att upprepas: hälsokontroller är inte per definition hälsofrämjande - från New Scientist:

"PSA-based screening for prostate cancer has no net benefit," concludes the US Preventive Services Task Force, which evaluates screening services. The dangers of PSA-based screening include a high rate of false positives, negative psychological effects, and complications associated with diagnostic biopsy and treatment, the task force says.

Steve Chapman tar upp ämnet hos Reason:

The idea of a harmless cancer may be hard to grasp. Typically, though, prostate cancer grows very slowly and has no symptoms, and by the time it gets around to killing you, you're already dead.

In the old days, countless males walked around with a song in their hearts and a spring in their steps, despite the malignant cells in their nether regions. They didn't know, and it didn't matter. But then scientists invented the PSA test, doctors started using it, and men by the millions found out they had prostate cancer.

Worse yet, they—or, rather, their doctors—proceeded to do something about it, namely surgery. When physicians wielding sharp instruments start removing stuff down there, the endeavor has definite drawbacks, such as sexual and urinary dysfunction.

What it doesn't have is definite benefits. A 2004 study found that for every 48 men who undergo operations for prostate cancer, only one will live longer as a result. But half will suffer permanent side effects affecting a certain cherished organ. Other studies are even more damning, finding that screening had zero effect on the death rate.

Det är alltså väldigt sunt att Socialstyrelsen förhåller sig kritiskt till de med jämna mellanrum föreslagna "masstesterna" av prostatacancer.

Andra kontroller har dock positiv effekt, så man bör som alltid hålla sig kritisk även till larmandet på kontrollfronten; exempelvis gällande ultraljud - NHS (Folkhälsoinstitutet i England) reder grundligt ut ultraljudslarmandet:

By examining scans of over 1,000 women the researchers found that under current guideline measurements around 0.4-0.5% of pregnancies that develop normally would have been misdiagnosed as non-viable. However, by slightly increasing the maximum sizes used to indicate a viable pregnancy, the researchers found that there were no cases of a viable pregnancy being misdiagnosed as a miscarriage. They also say that a repeat scan should take place if there is any doubt.

Despite what headlines have suggested, early pregnancy ultrasounds are invaluable and highly accurate diagnostic tools, and even using current guidelines, the vast majority of cases would be accurately diagnosed. However, this study has demonstrated there is room to further improve guidelines and the care of women in early pregnancy.

Tidigare på temat:
- Tio felbehandlingar per räddat liv

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