Epi in the News

1. This is an ecological study.
2. The exposure is humidity.
This measure could be biased by less accurate data as this study was based on analysis of secondary data. (Moreover, we know that the humidity measurement can be subjected to error due to defective instrument, erroneous calibration and temperature changes).
3. The outcome is suicide.
This measure could be biased by differences in detection and reporting of suicide. Moreover, the secondary data are often less accurate than the more direct measures.
4. Suicide is an example of an incidence measure.
5. Increased discomfort is not a confounder.
6. The effect modifiers are gender and age.

Thank you for the interesting read- an interesting insight into seasonal depression.

1) Definitely an ecological study- there is a geographical as well as longitudinal element (I say longitudinal because definitely there has been a difference in the weather over the years, and the link between humidity and rates of suicide have increased over the years).

2) The exposure here is humidity and heat waves. The problem with this measure is that the measurement is not standardized in all countries and of course, has not remained the same throughout the years. So there is going to be an element of measurement bias. Its likely to be more standardized and accurate in countries where the climate changes affect the life of the people.

3) The outcome is rate of suicide. The problem here would be that the estimate is unlikely to be accurate- not all suicides are reported as suicides.

4) Suicide would be an incidence measure- you count it when it happens... as a person is going to die only once

5) Nope not a counfounder... Its in the causal pathway- humidity leading to increased discomfort that leads to exacerbation of mental health problems.

6) Age (younger people), gender (women), previous history of mental health issues were all effect modifiers.

Fathima