Table 9.15 refers to a case-control study investigating a possible relationship between cataracts and the use of head coverings during the summer. Each case

reporting to a clinic for care for a cataract was matched with a control of the same sex and similar age not having a cataract. The row and column categories refer to the frequency with which the subject used head coverings. Analyze these data using models presented in this chapter. Interpret results.

Table 9.15 Control Cataract Case Always or Almost Always Frequently Occasionally Never Always or almost always 29 3 3 4 Frequently 5 0 1 1 Occasionally 9 0 2 0 Never 7 3 1 0 Source: J. M. Dolezal et al., Am. J. Epidemiol., 129: 559-568 (1989).