KEIAHER

ing drug users to ensure they have everything they need to inject safely any time they decide to inject. This device may reduce the likelihood of unsafe injecting.

Prisons Dr Avril Taylor (Ruchill Hospital, Scotland) reported on an outbreak of HIV in a Scottish prison where 12 injecting drug users tested HIV-positive; eight were infected in prison. The outbreak had the potential to affect a much larger group of people, given that 32 of 33 drug users identified in the prison reported needle sharing. Methadone treatment or mainte- nance and bleach distribution were recommended as a means of HIV prevention although it was acknowledged that bleach use in prison was imprac- tical and unlikely to be effective. Needle exchange was considered untenable by Scottish prison author- i ties.

A Swiss study reported on the use a vending machine to distribute needles and syringes to female prison inmates on a strict one-for-one basis. This program was supplemented with drug treat- ment programs (M. Buechi, Federal Office of Public Health, Switzerland,= This project is currently being evaluated, but it appears to provide a model for syringe exchange in prison. Levels of violence in prison in Switzerland are relatively low.

Overview The HIV epidemic continues to spread alarmingly in many parts of the world. Frustration, flagging public interest and lack of political will have con- tributed to a willingness to settle for preventive mea- sures which are necessary but not sufficient to con- trol the epidemic. These problems will not be solved by designing new posters. Achieving control requires a strong sense of commitment and the breaking down of societal and legislative barriers which have hindered HIV prevention in the last decade.

Margaret Kelaher National Drug and Alcohol Research Centre

University of New South Wales, Sydnq

References References are from the Proceedings of the Tenth AIDS Conference, 1994, Yokahama. The following references are abstract numbers from the proceedings.

1. Psl 14. 105C 2. Ts4 15. SR3 3. Ps4 16. 107C 4. TS3 17. PS20 5. 218C 18. 183C 6. PSll 19. 76c 7. 447D 20. 561C 8. ps6 21. 564c

22. 73c 9. Ps7 10. 301C 23. 559C

24. 463C 11. 302C 13. PS13 25. PD523

LETTER TO THE EDITOR

General practitioners’ estimates of the ideal benign-to-malignant ratio for excised pigmented lesions Del Mar et al., by describing the proportion of malig- nant pigmented lesions among those excised by gen- eral practitioners in Queensland, idenhfy the lack of a quantifiable performance indicator for removal of pigmented lesions by general practitioners.’ While 3 per cent of pigmented lesions in their sample were malignant, they wondered what proportion might be ideal.

It is timely to share an unpublished insight from our pretests of general practitioners attending one- day Cancer Council seminars about skin cancer con- ducted in six locations in rural New South Wales. Before the seminars, all participants were asked to complete a pretest, which included a section for those who had excised or biopsied lesions in the pre- vious 12 months. In this section, we asked: ‘In your view, what would be the ideal ratio of benign-to- malignant pigmented lesions excised by general practitioners?’, and ‘Do you remove too many benign pigmented lesions?’. We asked also for the number of pigmented lesions excised in the previ- ous 12 months and the number of these confirmed histologically as melanoma to calculate the propor- tion of confirmed melanomas per respondent.

Of the 136 general practitioners who completed pretests (93 per cent of seminar participants), 28 had not excised or biopsied skin lesions during the previous 12 months. Ofthe 108 who had, 26 (24 per cent) did not answer the first question about the ratio. Table 1 lists responses for the remaining 82.

Surprisingly, 26 of these 82 respondents (31 per cent) offered ideal ratios for which the number of malignant lesions would exceed the number of benign lesions. These responses may reflect a mis reading of the question, however. Seven respondents (9 per cent) indicated that the ideal ratio was 1:l. This also @ unachievable in practice. Of those 49 (60 per cent) who gave ratios that acknowledged the need to remove more benign lesions than malignant ones, replies ranged from 2:l to 1OO:l. The most fre- quently cited ratio was 1O:l.

In response to the next question, 56 respondents (68 per cent) indicated that they did not believe they removed too many benign lesions; 19 (23 per cent) thought they did and 6 (7 per cent) did not know (data missing for one). For those 33 who indi- cated a benign-tomalignant ratio of 1:l or less, 22 (67 per cent) indicated they did not remove too many benign lesions. Of the 49 who gave a benign- to-malignant ratio of more than one, 34 (69 per cent) indicated this. These proportions were not sig- nificantly different.

454 AUSTRALIAN JOURNAL OF PUBLIC HEALTH 1994 v a . 18 NO. 4

LETTER TO THE EDITOR

Table 1 : Generul pructitioners’ ideal benign-to-malignant ratio for excised pigmented skin lesions

Ratio Number

100: 1 50: 1 25: 1 20: 1 151 1O:l 9: 1 5: 1 4: 1 3: 1 2:l 1:l 1:2 1:4 1:5 1:8 1:lO 1:15 1 :20 1 :50 1:100

9 1 1 8 1 12 1 9 3 1 3 7 3 1 3 1 9 1 1 4 3

Eleven respondents provided insufficient infor- mation to calculate the malignant proportion of excised pigmented lesions. Of the remaining 97, 3.9 had not had a pigmented lesion confirmed as a melanoma. These 39 respondents had removed from 1 to 50 lesions (median 6, mode 10). For those 58 who had had at least one melanoma among excised pigmented lesions, the most common pro- portion of melanoma was calculated by us to be 10 per cent (reported by 9 respondents) and the medi- an, 5 per cent. The number of lesions excised in the previous 12 months by those who also had removed at least one melanoma ranged from 1 to 200.

Curiously, one respondent indicated that only one lesion had been removed and it was a melanoma (100 per cent malignant). There was no obvious association between the proportion we calculated and the respondents’ nominated ideal ratio, although the cell sizes were small.

Our results suggest that general practitioners have been given little assistance in conceptualising an objective performance indicator for judging the appropriateness of their excisions of pigmented skin lesions. Most of our respondents did not believe they removed too many benign lesions. The malignant proportion varied. One-third had excised pigment- ed lesions without removing a malignant lesion. Respondents’ perceptions of their current excision practices appeared to bear no relationship to a quantifiable indicator such as the benign-to-malig- nant ratio.

We recognise that our respondents are not repre- sentative of general practitioners, as they were expressing a need to learn more about skin cancer by attending the seminar. Thus, studies like that of Del Mar and his colleagues are essential to generate debate about standards of care in general practice. Research must continue in this important area, given the burden of illness inflicted by skin cancer and the key role of general practitioners in its early detection.

Jeanette Ward School of Medical Education,

University of New South Wales Kate Boyle

Department of Statistics, UniverstEy of Newmtle

Reference 1. Del Mar C, Green A, Cooney T, Cutbush K, eta]. Melanocytic

lesions excised from the skin: what percentage are malig- nant? AusfJArblicHcalth 1994; 18: 221-3.

BOOK REVIEWS

Evaluating health services’ effectiveness. A guide for health professionals, service managers and policy managers

A S. St Leger, H. Schnieden, J. P. Walsworth-Bell. Milton Keynes: Open University Press, 1992, 212 pp-, ISBN 0 335 09356 6.

St Leger, Schnieden and Walsworth-Bell state that the eval- uation of the effectiveness of health services differs from most areas of applied research ‘because it cannot take

‘place in isolation from the micropolitics and decision making procedures of health services’ (p. viii). Not sur- prisingly, their involvement in decision making in the health services and in teaching and research in the tertiary sector leads them to argue that the recent reforms of the British National Health Service (NHS) make it imperative to utilise this evaluative perspective.

The authors also stres that evaluation-demands a mul- tidisciplinary approach, in which participants ‘must accept that their individual disciplines do not necessarily dom- inate or own evaluative work‘ (p. 8). One can only hope that their call for humility is heard by some statisticians

and epidemiologists in Australia who think that they ‘own’ this evaluative area of public health.

Chapter 1 defines evaluation as ‘the critical assessment, on as objective a basis as possible, of the degree to which entire services or their component parts . . . fulfil stated goals’ (p. 1). The key elements of evaluation are standards and objectivity, its context includes structure, process and outcome, and its clinical and managerial framework is given through accreditation and quality assurance. Chapter 2 expands thesc concepts by illustrating hcalth service goals, aims and objectives and by explaining different indices of effectiveness. These include efficacy, efficiency, costeffectivenets, costutility, cost-benefit and quality of care.

Chapter 3 starts to develop skills by taking the reader through the steps of planning and executing health service evaluation. This is an excellent section which also stresses that players in evaluation for effectiveness are often best placed to advocate change. However, the authors also warn that ‘results from which no action flows are worthless’ (p. 28). Chapter 4 is also extensive when it gives details of using routincly gathered data which can assist in evaluation. Some of the sources of data are specific to the British scene, but the epidemiological data,

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