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SummaryIn the course of an investigation of melanocytic naevus development in Queensland, Australia, whole-body naevus counts of 66 adolescents were performed separately by two nurse examiners on two occasions on average 4 weeks apart. There was good agreement between the two examiners for counts of total naevi on the whole body (intra-class correlation coefficient = 0.96) and at selected subsites (face, neck, back, upper arms, lower arms). Agreement was lower when raised naevi only were counted (0.83). Intra-examiner repeatability was high for both nurses, particularly for the more experienced examiner (intra-class correlation coefficients = 0.98 and 0.91 for total naevi on the whole body), and was consistently better when all naevi were counted rather than naevi of a particular size. Independent counts of naevi on the back using a computer imaging technique were reproducible (intra-class correlation coefficient = 0.92), but showed only moderate agreement with counts by the nurse examiners. Overall, these results demonstrate high comparability of naevus counts between and within similarly trained examiners. They do not support the common practice in epidemiological studies of restricting counts to naevi larger than 2 mm, or of counting raised naevi only.Melanoma is an increasingly important public health problem in white-skinned populations throughout the world. In Australia, it is currently the second most common cause of cancer death, and its rapidly increasing incidence is expected to overtake that of all other cancers, with the exception of non-melanoma skin cancer, within the next decade (MacLennan et al., 1992). The number of naevi on the body is the strongest known predictor of melanoma risk and, as such, the reliable and accurate measurement of naevus numbers is important for ongoing individual risk assessment, in studies of naevus prevalence between and within populations over time and in aetiological investigations, in which the number of naevi is invariably a potential confounder of other melanoma risk factors (Green & Swerdlow, 1989).Counting naevi and consistently differentiating these from freckles and other pigmented lesions is one of the more difficult tasks in melanoma research (Green et al., 1991). Nevertheless, some limited data available indicate that reasonable agreement of naevus counts between and within examiners is possible. Roush et al. (1991) reported good agreement between examiners' counts of all naevi on the whole body (intra-class correlation coefficient = 0.92) and arm (0.88) of 153 melanoma patients at the Yale Melanoma Unit. Agreement for raised naevi on the arm was considerably lower (0.36) because of differences of opinion about what was considered palpable. In a small study in Canada (Walter et al., 1991), intra-examiner repeatability of naevus counts on the mid-left arm of eight volunteers, measured by the intra-class correlation coefficient, varied from 0.55 to 0.81 for the five examiners, and tended to be highest among those most experienced.Both of these studies were con...

1987 and reported to the Queensland Cancer Registry. Of 6,404 cases for whom we were able to obtain a contract address and the doctor's agreement, 1,924 index subjects were selected from 5,475 (85%) who responded to a brief one-page questionnaire about family history of melanoma.The index subjects, here referred to as probands, comprised all cases who reported one or more first degree relatives with melanoma, and an equal sized random sample of cases who reported no first degree relatives with melanoma. Data collection Surrogate reports by probands about relatives A questionnaire was mailed to the probands, asking for information about standard melanoma risk factors for themselves and for their first degree relatives (parents, siblings, and children); the names and addresses of these relatives; and whether any relatives had had a melanoma diagnosed by a doctor. An abbreviated version of the risk factor questionnaire, asking about the same items but without cross-reporting on family members, was then mailed to the probands' living first degree relatives aged between 18 and 75 years. The standard risk factors studied were pigmentary traits (hair colour at age 21, and skin colour); sensitivity of the skin to the sun (average propensity to burn, ability to suntan, and tendency to acute sunburn); the number of episodes of painful sunburn; and a qualitative rating of the number of moles on the body (none, few, a moderate number, and very many moles, as represented in four graphical illustrations (Dubin et al., 1986)). Questions were asked with identical wording in both versions of the risk factor questionnaire, except that a 'Don't know' category was included in most questions in which cross-reporting was required (see Appendix).One thousand, two hundred and fifty-nine (65%) probands returned the cross-reporting questionnaire, of whom 1,242 named one or more first degree relatives. In many instances the same person was mentioned by more than one proband, and a total of 9,078 reported relatives comprised 8,992 individuals. The questionnaire without cross-reporting was