Hormone Replacement Therapy

Part 1: An epidemiological study showed that women who undertook hormone replacement therapy (HRT) had a lower-than-average incidence of coronary heart disease (CHD). Was HRT a cause for the reduced incidence of CHD?

Your vote: Yes No

Part 2: A clinical trial has shown that subjects undergoing HRT subsequently had a statistically significant increase in occurrence of CHD over those subjects who did not. Was HRT a cause for the increased incidence of CHD?

Your vote: Yes No

Part 3: Assuming that both investigations were correctly conducted, Is it possible to reconcile these seemingly contradictory results?

Your vote: Yes No