Truth after death

Diagnosis is central to medicine. In spite of tremendous diagnostic technological advances, no infallible test exists and in the complex diagnostic process the physician may well get lost. The ultimate feedback on the accuracy of diagnosis is the autopsy. Five patients illustrate that the autopsy may disclose unexpected results. The first patient was a 9-year-old girl who suffered from daily abdominal spasmodic pain but each time recovered. She died suddenly; autopsy revealed intestinal intussusception. A 46-year-old man who was treated for hypertension developed pain in the chest and the lower back, but there were no other signs of myocardial infarction. He died suddenly; autopsy revealed a dissecting aortic aneurysm with rupture in the left pleural cavity. A 21-year-old woman, an excellent swimmer, drowned during a swim in the sea. Autopsy revealed severe widespread coronary disease with multiple myocardial infarction. A 32-year-old Surinam woman developed acute coma and died from cardiorespiratory arrest. At autopsy she had massive pulmonary embolism and generalized lymphadenopathy due to sarcoidosis. The last patient, a 32-year-old woman suffered from fatigue after her fourth child was born. She was admitted with severe dyspnoea and her chest X-ray showed interstitial fibrosis. She died presently and autopsy revealed metastatic colon carcinoma with pulmonary lymphangitis carcinomatosa. Systematic reviews of the results of autopsies show no decline in the percentage of false diagnoses and/or unexpected findings in spite of the enormous growth of the diagnostic armamentarium. Although we may radiologically 'slice' the body in incredible detail or investigate human cells at the molecular level, the autopsy has by no means become obsolete and is an invaluable tool for quality control and teaching.     

Damned if you do, damned if you don't: subgroup analysis and equity

The final report from the WHO Commission on the social determinants of health recently noted: 'For policy, however important an ethical imperative, values alone are insufficient. There needs to be evidence on what can be done and what is likely to work in practice to improve health and reduce health inequities.' This is challenging, because understanding how to reduce health inequities between the poorest and better-off members of society may require a greater use of subgroup analysis to explore the differential effects of public health interventions. However, while this may produce evidence that is more policy relevant, the requisite subgroup analyses are often seen as tantamount to statistical malpractice. This paper considers some of the methodological problems with subgroup analysis, and its applicability to considerations of equity, using both clinical and public health examples. Finally, it suggests how policy needs for information on subgroups can be met while maintaining rigour.