formers given ESWL and those treated without ESWL (i.e., control subjects). They did find, however, that although not yet meeting the definition of hypertension the diastolic blood pressure of the patients treated with ESWL was rising significantly faster than that of the control subjects (p < 0.001). These observations led Lingeman and associates to note that this "is worrisome, especially given the low number of shock waves administered to patients treated in this study." Moreover, of the patients who received only percutaneous nephrostolithotomy (PCNL) for the treatment of their stones "none became newly hypertensive following treatment." Although complicated, evidence such as this shows that questions regarding the effectiveness and safety of ESWL have not, as yet, been definitively answered. The data of Lingeman and associates suggest that an RCT comparing ESWL and PCNL would be helpful in resolving this issue. Moreover, there are those who believe that PCNL results in a higher stone-free rate after treatment than does ESWL.3,4 The consensus regarding the assessment of technology in this country5'6 and elsewhere7 is changing to reflect a more scientific approach to the problem. Nowhere has this been more evident than in a recent CMAJ article,5 in which Ontario's Technology Subcommittee of the Working Group on Critical Care noted: "The assessment of technology is being addressed in a haphazard way." The subcommittee concluded: "Of foremost importance is a scientifically rigorous approach to all aspects of technology evaluation." There can be little doubt that this is a reference to RCTs, a form of evaluation that has only recently - long after its diffusion been applied to ESWL. Unless efficacy and effectiveness have been established in a 1076
CAN MED ASSOCJ 1991; 145(9)
scientifically satisfactory manner no valid claim can be made with respect to the economic efficiency of a technology.8 ESWL is a classic example of a technology for which such claims have preceded the resolution of the effectiveness issue. The replacement of an existing technology with a cheaper, ineffective technology is as irrational as replacing it with a more costly, ineffective technology. The Canadian taxpayer and health care consumer needs to be assured that scientifically valid linkages can be drawn between the effectiveness and economic efficiency of a medical technology before its use becomes widespread. We believe that the movement toward RCTs in the scientific evaluation of medical technology is good and that our present statutes must support this change. In our paper we offered suggestions to augment such changes, and we heartily invite others to join the debate. We are confident that from this process will emerge a system of assessment more in keeping with today's needs, which will truly reflect the best interests of this nation. Lawrence C. Wiser, MD, MHSA 4760 Pasqua St. Regina, Sask. Richard H.M. Plain, PhD Professor of economics John B. Dossetor, MD, PhD, FRCPC Director of the Joint-Faculties Bioethics Project University of Alberta Edmonton, Alta.
References 1. McKinlay JB: From "promising report" to "standard procedure": seven stages in the career of a medical innovation. Milbank Mem Fund Q 1981; 59: 374411 2. Lingeman JE, Woods JR, Toth PD: Blood pressure changes following extracorporeal shock wave lithotripsy and other forms of treatment for nephrolithiasis. JAMA 1990; 263: 1789-1794 3. Mays N, Challah S, Patel S et al: Clinical comparison of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy in treating renal
calculi. BMJ 1988; 297: 253-258 4. Lingeman JE, Coury TA, Newman DM et al: Comparison of results and morbidity of percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy. J Urol 1987; 138: 485-490 5. Technology Subcommittee of the Working Group on Critical Care, Ontario Ministry of Health: The assessment of technology in Ontario's critical care system. Can Med Assoc J 1991; 144: 1613-1615 6. Idem: Guidelines for medical technology in critical care. Ibid: 1617-1622 7. Passamani E: Clinical trials - Are they ethical? N Engl J Med 1991; 324: 15891591 8. Drummond MF, Stoddart GL, Torrance GW: Methods for the Economnic Evaluation of Health Care Programs, Oxford U Pr, New York, 1987: 20
Women and academic medicine T n he opening sentence of the article "Growing number of women physicians not reflected in academic medicine" (Can Med Assoc J 1991; 144: 1313-1315), by Drs. Kari Smedstad and May Cohen, claims that "women are under-represented in academic medicine in Canada." This under-representation is inferred from the fact that from 1960 to 1989 the percentage of medical degrees earned by women in Canada rose steadily from 10.1% to 38.3%, yet only 14% of full-time faculty are women. (The 14% does not reflect the current situation, as the article implies, but refers to the 1986-87 academic year.) I was surprised to see the article's bold headline, because a few months ago I submitted for publication to CMAJ an article that dealt seriously with whether women faced discrimination in access to academic careers in medicine. My article was based on hard data covering 100% of fulltime academics appointed to all 16 Canadian faculties of medicine in the 1986-87 academic year. The inclusion of all full-time academics made possible accurate LE ler NOVEMBRE 1991
counts by age, rank, educational background, discipline taught etc. The article also compared, by age and sex, the numbers of medically qualified academics with the total pool of people who earned an MD degree in Canada. This comparison is crucial if any judgement of over-representation or underrepresentation is to be based on objective criteria rather than unsubstantiated assertion. CMAJ had the opportunity to publish these landmark data for Canada but turned the article down. What a shame, because the results confound the widely held belief that women have not had the same opportunity for a career in academic medicine as men. The principal findings are summarized in Table 1. Note that the proportion of medically qualified academics who are women matches almost perfectly the proportion of women in each graduating cohort. To quote from the article, Once the educational history of the past is included in the variables examined, qualified women are represented on medical school faculties in the same proportion as qualified men. The two principal determinants of the number of women full-time faculty
members in 1986/87 were the proportions of women in successive graduating cohorts of Canadian medical schools [and] the rate of hiring over the years as reflected in the age structure of faculty.
ical Colleges for a copy of the article, entitled "Women in academic medicine in Canada: Are women subject to discrimination?"
The importance of these data can hardly be exaggerated at a time when our universities are under constant pressure to alter the traditional bases of hiring academics - excellence and productivity - to overcome presumed under-representation. Ironically, it is the extraordinary rapidity with which women have entered medicine that has led to the perception of underrepresentation in academia. People do not generally become qualified for academic careers until 10 or more years after earning the MD degree and do not generally achieve the rank of full professor until 25 or more years after graduation. In times of very rapid change, the sex composition of undergraduate classes is a very poor indicator of the sex composition of the available pool of people qualified for an academic appointment, especially at senior ranks. Those interested may write to the Association of Canadian Med-
Eva Ryten Director Office of Research and Information Services Association of Canadian Medical Colleges 1006-151 Slater St. Ottawa, ON KIP 5N1
[Drs. Smedstad and Cohen reply.] Ms. Ryten's comments on women in academic medicine are interesting and, indeed, encouraging. The numbers quoted in our article were based on information available to us at the time of writing. We used Ryten's published work extensively, as well as more recent US publications, in drawing our conclusions. We certainly respect Ryten's work and find the table interesting. Although there now are equitable numbers of women graduating in medicine, there are still few female role models within the faculties who can encourage young medical graduates to plan a career in academic medicine. We are
Table 1: Numbers and proportions of full-time faculty with MD degree by age and sex, 1986-87, compared with proportions of MD degrees awarded to women of corresponding ages, Canadian faculties of medicine
Age (yr) of faculty < 30 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 > 69 Total
Approximate year MD earned* 1981-82 1976-80 1971-75 1966-70 1961-65 1956-60 1951-55 1946-50 1941-45 < 1941
% of MDs earned by women in Canada in those years 33.8 28.9 18.4 11.8 9.1 6.5 6.1 7.5 5.6 4.4t
Women as % of
full-time faculty 50.0 26.3 18.7 13.8 8.2 6.5 7.2 6.8 5.7 0.0 12.3
Nos. of full-time faculty Men 19 246 636 700 667 614 514 357 83 6 3842
Women 19 88 146 112 59 43 40 26 5 0
Total
538
4380
38 334 782 812 726 657 554 383 88 6
*Assuming age at graduation years. tAverage of 10 years prior to 1941. = 24
NOVEMBER 1, 1991
CAN MED ASSOC J 1991; 145 (9)
1077
CAN MED ASSOCJ 1991; 145(9)
scientifically satisfactory manner no valid claim can be made with respect to the economic efficiency of a technology.8 ESWL is a classic example of a technology for which such claims have preceded the resolution of the effectiveness issue. The replacement of an existing technology with a cheaper, ineffective technology is as irrational as replacing it with a more costly, ineffective technology. The Canadian taxpayer and health care consumer needs to be assured that scientifically valid linkages can be drawn between the effectiveness and economic efficiency of a medical technology before its use becomes widespread. We believe that the movement toward RCTs in the scientific evaluation of medical technology is good and that our present statutes must support this change. In our paper we offered suggestions to augment such changes, and we heartily invite others to join the debate. We are confident that from this process will emerge a system of assessment more in keeping with today's needs, which will truly reflect the best interests of this nation. Lawrence C. Wiser, MD, MHSA 4760 Pasqua St. Regina, Sask. Richard H.M. Plain, PhD Professor of economics John B. Dossetor, MD, PhD, FRCPC Director of the Joint-Faculties Bioethics Project University of Alberta Edmonton, Alta.
References 1. McKinlay JB: From "promising report" to "standard procedure": seven stages in the career of a medical innovation. Milbank Mem Fund Q 1981; 59: 374411 2. Lingeman JE, Woods JR, Toth PD: Blood pressure changes following extracorporeal shock wave lithotripsy and other forms of treatment for nephrolithiasis. JAMA 1990; 263: 1789-1794 3. Mays N, Challah S, Patel S et al: Clinical comparison of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy in treating renal
calculi. BMJ 1988; 297: 253-258 4. Lingeman JE, Coury TA, Newman DM et al: Comparison of results and morbidity of percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy. J Urol 1987; 138: 485-490 5. Technology Subcommittee of the Working Group on Critical Care, Ontario Ministry of Health: The assessment of technology in Ontario's critical care system. Can Med Assoc J 1991; 144: 1613-1615 6. Idem: Guidelines for medical technology in critical care. Ibid: 1617-1622 7. Passamani E: Clinical trials - Are they ethical? N Engl J Med 1991; 324: 15891591 8. Drummond MF, Stoddart GL, Torrance GW: Methods for the Economnic Evaluation of Health Care Programs, Oxford U Pr, New York, 1987: 20
Women and academic medicine T n he opening sentence of the article "Growing number of women physicians not reflected in academic medicine" (Can Med Assoc J 1991; 144: 1313-1315), by Drs. Kari Smedstad and May Cohen, claims that "women are under-represented in academic medicine in Canada." This under-representation is inferred from the fact that from 1960 to 1989 the percentage of medical degrees earned by women in Canada rose steadily from 10.1% to 38.3%, yet only 14% of full-time faculty are women. (The 14% does not reflect the current situation, as the article implies, but refers to the 1986-87 academic year.) I was surprised to see the article's bold headline, because a few months ago I submitted for publication to CMAJ an article that dealt seriously with whether women faced discrimination in access to academic careers in medicine. My article was based on hard data covering 100% of fulltime academics appointed to all 16 Canadian faculties of medicine in the 1986-87 academic year. The inclusion of all full-time academics made possible accurate LE ler NOVEMBRE 1991
counts by age, rank, educational background, discipline taught etc. The article also compared, by age and sex, the numbers of medically qualified academics with the total pool of people who earned an MD degree in Canada. This comparison is crucial if any judgement of over-representation or underrepresentation is to be based on objective criteria rather than unsubstantiated assertion. CMAJ had the opportunity to publish these landmark data for Canada but turned the article down. What a shame, because the results confound the widely held belief that women have not had the same opportunity for a career in academic medicine as men. The principal findings are summarized in Table 1. Note that the proportion of medically qualified academics who are women matches almost perfectly the proportion of women in each graduating cohort. To quote from the article, Once the educational history of the past is included in the variables examined, qualified women are represented on medical school faculties in the same proportion as qualified men. The two principal determinants of the number of women full-time faculty
members in 1986/87 were the proportions of women in successive graduating cohorts of Canadian medical schools [and] the rate of hiring over the years as reflected in the age structure of faculty.
ical Colleges for a copy of the article, entitled "Women in academic medicine in Canada: Are women subject to discrimination?"
The importance of these data can hardly be exaggerated at a time when our universities are under constant pressure to alter the traditional bases of hiring academics - excellence and productivity - to overcome presumed under-representation. Ironically, it is the extraordinary rapidity with which women have entered medicine that has led to the perception of underrepresentation in academia. People do not generally become qualified for academic careers until 10 or more years after earning the MD degree and do not generally achieve the rank of full professor until 25 or more years after graduation. In times of very rapid change, the sex composition of undergraduate classes is a very poor indicator of the sex composition of the available pool of people qualified for an academic appointment, especially at senior ranks. Those interested may write to the Association of Canadian Med-
Eva Ryten Director Office of Research and Information Services Association of Canadian Medical Colleges 1006-151 Slater St. Ottawa, ON KIP 5N1
[Drs. Smedstad and Cohen reply.] Ms. Ryten's comments on women in academic medicine are interesting and, indeed, encouraging. The numbers quoted in our article were based on information available to us at the time of writing. We used Ryten's published work extensively, as well as more recent US publications, in drawing our conclusions. We certainly respect Ryten's work and find the table interesting. Although there now are equitable numbers of women graduating in medicine, there are still few female role models within the faculties who can encourage young medical graduates to plan a career in academic medicine. We are
Table 1: Numbers and proportions of full-time faculty with MD degree by age and sex, 1986-87, compared with proportions of MD degrees awarded to women of corresponding ages, Canadian faculties of medicine
Age (yr) of faculty < 30 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 > 69 Total
Approximate year MD earned* 1981-82 1976-80 1971-75 1966-70 1961-65 1956-60 1951-55 1946-50 1941-45 < 1941
% of MDs earned by women in Canada in those years 33.8 28.9 18.4 11.8 9.1 6.5 6.1 7.5 5.6 4.4t
Women as % of
full-time faculty 50.0 26.3 18.7 13.8 8.2 6.5 7.2 6.8 5.7 0.0 12.3
Nos. of full-time faculty Men 19 246 636 700 667 614 514 357 83 6 3842
Women 19 88 146 112 59 43 40 26 5 0
Total
538
4380
38 334 782 812 726 657 554 383 88 6
*Assuming age at graduation years. tAverage of 10 years prior to 1941. = 24
NOVEMBER 1, 1991
CAN MED ASSOC J 1991; 145 (9)
1077
