1. In some population, prevalence of hypertension (HT) among male is 0.55 and among female is 0.4.
   • STANDARD Assuming that spouses' HT status, what are expected proportions of couples where (a) both spouses are ht (b) husband is HT and wife is not (c) wife is HT and husband is not (d) both spouses are not HT?
   • HIGH Spouses' HT status is NOT independent. The risk in people, whose husband has HT, is 1.5 higher compared to people whose husband has no HT. What are expected proportions of couples where (a) both spouses are HT (b) husband is HT and wife is not (c) wife is HT and husband is not (d) both spouses are not HT?
   • Considering previous example, what is the relative risk of husbands whose wife has HT compared to the risk in husbands whose wife has no HT?
2. HIGH Read the paper by Hippisley-Cox et al., BMJ 2002;325:636. The paper gives the estimates what is relative risk in female to have depression when spouse has depression (as compared to women whose husband has no depression).
   • Which participants were defined as "depressed"?
   • What was the proportion of depression among male and female?
   • Use age-adjusted RR as if it was unadjusted RR, and answer, what are expected proportions of couples where (a) both spouses are depressed (b) husband is depressed and wife is not (c) wife is depressed and husband is not (d) both spouses are not depressed?
   • How the fact that you use age-adjusted RR as unadjusted RR affects your results?