These results suggest that the unmodified EPI household sampling scheme may be adequate for rapid appraisal of morbidity prevalence or nutritional status of communities, but that it may not be appropriate for surveys which cover a wider range of topics such as health care, or seek to examine the association of health or nutrition with explanatory factors such as education and socioeconomic status. Other factors such as cost and the ability to monitor interviewers' performance should also be taken into account.

assessment of cognitive deficits. In: Crook r, Ferris S, Bartus R, eds. Assessment in geriatoic psychopharmacology. New Canaan, Conn: Marc Powlev, 1983:137-

To quantify the host genetic component of meningococcal disease (MD) susceptibility, the sibling risk ratio (λs) was calculated as the ratio of observed MD cases among 845 siblings of 443 UK Caucasian cases to that expected, calculated from age-calendar year specific rates for England and Wales. Twenty-seven siblings contracted MD compared with an expected 0·89, generating a λs value of 30·3. Overestimation of λs due to Neisseria meningitidis exposure was minimized by excluding siblings with MD onset within set time points of the index case. Irrespective of whether siblings contracted MD more than 1, 3, 6, 9 or 12 months after the index case, the λs varied slightly (λs range: 8·2–11·9), suggesting that host genetic factors may contribute approximately one third of the total λs. Social class distribution did not differ between MD cases and the general population of England and Wales. This study is the first to calculate λs for MD and establishes that susceptibility to MD has a significant host genetic component.

No abstract