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Setting goals for reductions in Canadian cesarean delivery rates: Benchmarking medical practice patterns
Setting goals for reductions in Canadian cesarean delivery rates: Benchmarking medical practice patterns Vincent V. Richman, MBA, PhD Halifax, Nova Scotia, Canada OBJECTIVE: The objective of this study was to present a structured method for determining achievable cesarean rate goals and specifying which hospitals should receive focused attention. STUDY DESIGN: Hospital level data from the largest 239 Canadian maternity units were analyzed for 19881989, when the number of Canadian cesarean deliveries peaked. Cesarean rate statistical limits within the largest, intermediate-sized, and smallest maternity unit classifications were successively set at the 75th, 50th, and 25th percentiles. RESULTS: The national impact resulting from using the 75th percentile rate as the assigned statistical cesarean rate limit was 2707 (50th 5568; 25th 11,018) fewer cesarean deliveries. CONCLUSION: Benchmarking provides a structured perspective on defining goals and on estimating how much change is required and at which hospitals. (Am J Obstet Gynecol 1999;181:635-7.)
Key words: Benchmarking, Canada, cesarean delivery, health services research, physicians’ practice patterns
It is generally recognized that the cesarean delivery rate is too high.1, 2 The cesarean delivery rate increased in both the United States and Canada by a factor of 4 from the mid-1960s to the late 1980s.3-6 These increases have not been uniform. There are large cross-sectional differences among comparable patient populations across Canada (and across the United States).6-8 Since the early 1980s, there have been formal pronouncements from professional medical and obstetrics organizations stating that the cesarean rate is too high and cannot be medically justified.1, 9-12 Although there is general agreement that the cesarean rate is too high, there is no agreement on what level it should be.13, 14 There are a number of approaches that have led to recommendations. One approach is to base the recommendation on a country, or part of a country, with a desirable cesarean policy and a comparable population. It is difficult, however, to identify which cesarean rate is desirable. A second approach is to examine the historical cesarean rate records in a country and to select an appropriate level from the past. The difficulty of deciding what is appropriate remains. A third approach is to determine that a certain reduction in rates is possible, on the basis of clinical judgment as to what improve-
From AlgoPlus Consulting Limited. Received for publication December 4, 1998; revised March 17, 1999; accepted April 9, 1999. Reprint requests: Vincent V. Richman, MBA, PhD, AlgoPlus Consulting Limited, 5675 Spring Garden Rd, Suite 502, Halifax, Nova Scotia, Canada B3J 1H1. Copyright © 1999 by Mosby, Inc. 0002-9378/99 $8.00 + 0 6/1/99216
ments in practice are perceived as appropriate. A fourth approach is to select a specific hospital or geographic area where cesarean clinical guidelines are rigorously followed and to use that rate as a national goal. The last 2 approaches particularly rely on professional judgment as to what is medically appropriate. They shed little light on the extent of change in terms of the range and distribution of existing medical practice among hospitals. This article introduces a fifth approach, benchmarking, for the determination of an achievable cesarean rate. Benchmarking determines the target cesarean rate in terms of the distribution of existing practice. Methods The method of benchmarking to analyze cesarean rates does not calculate theoretic optimums15, 16; instead, the performance of similar institutions is analyzed and compared. The minimum standard of accepted performance is assumed to be one point along the diverse range of performance values. The analysis of the distribution of cesarean rates sidesteps the issue of appropriate medical practice and focuses on realistic implementation and achievability. The assigned statistical cesarean rate limits, in these calculations, were rates that constituted the 75th, 50th, and 25th percentiles of Canadian maternity units, although no judgment was made concerning which percentile was appropriate. The underlying assumption was that maternity units that are classified as treating comparable patient populations are expected to have comparable cesarean rates and the performance goal is determined by the existing 635
636 Richman
September 1999 Am J Obstet Gynecol
Table I. Characteristics of maternity unit Cesarean rate distribution
Largest units Intermediate units Smallest units TOTAL
Maternity beds per unit
No. of maternity units
62-127 24-60 10-24 10-127
23 99 117 239
Total maternity beds No.
%
1852 3760 1876 7488
25 50 25 100
Total cesarean deliveries (No.)
25th Percentile (%)
16,487 34,125 10,961 61,573
50th Percentile (%)
75th Percentile (%)
20.4 20.0 18.3 19.3
23.0 22.2 21.8 22.2
19.1 16.9 14.2 15.5
Table II. Impact of benchmarking cesarean rates: Change in numbers of cesarean deliveries Original cesarean deliveries
Largest units Intermediate units Smallest units TOTAL
Rate (%)
No.
20.4 20.2 18.1 19.8
16,487 34,125 10,961 61,573
75th Cesarean rate percentile
50th Cesarean rate percentile
25th Cesarean rate percentile
Assigned norm (%)
Resulting cesareans (No.)
Change in number
Assigned norm (%)
Resulting cesareans (No.)
Change in number
Assigned norm (%)
Resulting cesareans (No.)
Change in number
23.0 22.2 21.8
16,243 32,169 10,454 58,866
–244 –1956 –507 –2707
20.4 20.0 18.3
15,500 30,885 9,620 56,005
–987 –3240 –1341 –5568
19.1 16.9 14.2
14,849 27,658 8,048 50,555
–1,638 –6,467 –2,913 –11,018
distribution of medical practice. Benchmarks were established for each of the 3 size categories of maternity units, the largest, intermediate-sized, and smallest units. The data were obtained from Statistics Canada. All Canadian hospitals are required to complete the Annual Return of Health Care Facilities—Hospitals, the form from which these data are derived.17 The study examines data from 1988-1989, the year of the highest number of cesarean deliveries. The study analyzed the 239 hospitals that had at least 10 maternity beds throughout 19831992. The cesarean delivery rate was calculated by dividing the number of cesarean deliveries by the number of newborn infants. The results from dividing by the number of maternity admissions were similar. The maternity units were classified on the basis of maternity unit size. The largest units were expected to have the most resources for treating patients with more complex conditions, whereas the smallest units were expected to treat those with less complex conditions. The 239 maternity units were stratified on the basis of size into 3 size classes. The purpose of this stratification was to establish separate benchmarks for each class. The largest and smallest maternity units containing 25% of the study group’s maternity unit beds were assigned to the largest and smallest maternity unit category (Table I). Three estimates were calculated by successively setting the 75th, 50th, and 25th percentiles within each maternity unit classification as the assigned statistical cesarean
rate limit. For the purposes of the calculation, maternity units with higher cesarean rates than the assigned statistical cesarean rate limit were set to the assigned rate limit. Those maternity units with lower cesarean rates did not have their cesarean rates changed. Results The 239 hospitals delivered 310,464 neonates and performed 61,573 cesarean deliveries. These totals accounted for 82% of all newborn infants and 85% of all cesarean deliveries in Canada during 1988-1989. The cesarean rate medians were similar for the 3 maternity unit categories. The interquartile differences increased when there were more units within a category. Table I describes the characteristics and distributions of cesarean rates for each of the largest, intermediatesized, and smallest maternity unit categories, as well as for the total 239 maternity units. Table II lists the results from setting the assigned statistical cesarean rate limit within each category at the 75th, 50th, and 25th percentiles, including the resulting cesarean rates, the numbers of cesarean deliveries, and the numbers of fewer cesarean deliveries for each category and overall. Comment The benchmarking method brings 5 advantages to the analysis of medical practice patterns. First, the focus is on the existing distribution of rates. Second, the method is easy to implement and requires no professional judgment. Third, the specific maternity units that need to
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change are identified. Fourth, the change in the number of cesarean deliveries at each maternity unit is calculated. Finally, the method is generalizable to all practice patterns. The first advantage of focusing on the existing distribution of performance brings any recommendations into the realm of practicality. The emphasis on explicitly stating that maternity units with rates above a specified percentile should change their rates highlights the practicality and feasibility of the recommendation. The second advantage is the ease of implementation. Target rates are explicitly determined in terms of the percentage of maternity units that should change their rates. The exclusive focus on the distribution of rates removes the need for professional knowledge or judgment. This removes the need for consensus statements or agreements about practice guidelines. The third advantage is that the specific maternity units that need to change are identified. The knowledge of both the numbers of maternity units that should change their rates and the amount of that change provides a perspective on the ease and practicality of achieving the recommended goal. The fourth advantage is that the effect on the numbers of cesarean deliveries at each maternity unit is calculated. The resulting decrease in cesarean deliveries is the combined effect of the number of deliveries and the magnitude of the rate change. When there are limited resources available for intervention efforts to effect change, it is useful to identify maternity units where there is the largest potential effect, the largest potential decreases in cesarean deliveries. The final advantage is one of generalizability. Benchmarking can be applied to the analysis of other procedures—obstetric and nonobstetric, surgical and nonsurgical. The only requirement is that there be wide variation in the application of clinical judgment and, consequently, diversity in practice rates. Benchmarking assumes that there is a reasonable classification process for determining comparable maternity units that treat comparable patient populations. This information was implied by the maternity unit size. The biggest and smallest maternity units had similar cesarean rate medians. Because the medians were similar, there is little basis for concern about whether the classification of the size of the unit was accurate. Benchmarking is a statistical process; it does not indicate which cesarean rate is ideal or safe. The selection of
the 75th, 50th, and 25th percentiles followed conventional practice in using quartiles; other percentiles could have been used. The assistance of Statistics Canada in providing the data is appreciated. REFERENCES
1. Consensus Development Conference on Cesarean Childbirth, September 1980, sponsored by the National Institute of Child Health and Human Development. Bethesda (MD): National Institutes of Health; 1981. Publication No.: 82-2067. 2. Sakala C. Medically unnecessary cesarean section births: introduction to a symposium. Soc Sci Med 1993;37:1177-98. 3. Centers for Disease Control and Prevention, National Center for Health Statistics, Office of Vital and Health Statistics Systems. Rates of cesarean delivery—United States, 1991. MMWR Morb Mortal Wkly Rep 1993;42:285-9. 4. Centers for Disease Control and Prevention, National Center for Health Statistics, Office of Vital and Health Statistics Systems. Rates of cesarean delivery—United States, 1993. MMWR Morb Mortal Wkly Rep 1995;44:303-7. 5. Nair C. Trends in cesarean section deliveries in Canada. Health Rep 1991;3:259-79. 6. Millar W, Nair C, Wadhera S. Declining cesarean section rates: a continuing trend? Health Rep 1996;6:17-24. 7. Placek P, Taffel S. Recent patterns in cesarean delivery in the United States. Obstet Gynecol Clin North Am 1988;15:607-27. 8. American Hospital Association. AHA hospital statistics: the AHA profile of United States hospitals. 1993-94 ed. Chicago: The Association; 1993. 9. American College of Obstetricians and Gynecologists. Guidelines for vaginal delivery after a cesarean childbirth. Statement of the Committee on Obstetrics: Maternal and Fetal Medicine. Washington: The College; 1982. 10. American College of Obstetricians and Gynecologists, Committee on Obstetrics: Maternal and Fetal Medicine. Guidelines for vaginal delivery after a previous cesarean childbirth. Washington: The College; 1984 Nov. 11. American College of Obstetricians and Gynecologists, Committee on Obstetrics: Maternal and Fetal Medicine. Guidelines for vaginal delivery after a previous cesarean birth. Washington: The College; 1988. 12. Society of Obstetricians and Gynaecologists of Canada, Panel of the National Consensus Conference on Aspects of Cesarean Births. Indications for cesarean sections: final statement of the Panel of the National Consensus Conference on Aspects of Cesarean Birth. Can Med Assoc J 1986;134:1348-52. 13. Helewa M. Cesarean sections in Canada: what constitutes an appropriate rate? J Soc Obstet Gynaecol Can 1995;17:237-46. 14. Flamm BL, Quilligan EJ, editors. Cesarean section: guidelines for appropriate utilization. New York: Springer-Verlag; 1995. 15. Garrison RH, Noreen EW, Chesley GR, Carroll RF. Managerial accounting: concepts for planning, control, decision making. Fourth Canadian edition. Toronto: McGraw-Hill Ryerson; 1998. 16. Horngren CT, Foster G, Datar SM, Teall HD. Cost accounting: a managerial emphasis. First Canadian edition. Scarborough (Ontario, Canada): Prentice Hall Canada; 1997. 17. Statistics Canada. 1991. Hospital annual statistics 1988-89. Volume 1: beds and patient movement. Health Rep (Suppl 20) 1991:3(4).
Key words: Benchmarking, Canada, cesarean delivery, health services research, physicians’ practice patterns
It is generally recognized that the cesarean delivery rate is too high.1, 2 The cesarean delivery rate increased in both the United States and Canada by a factor of 4 from the mid-1960s to the late 1980s.3-6 These increases have not been uniform. There are large cross-sectional differences among comparable patient populations across Canada (and across the United States).6-8 Since the early 1980s, there have been formal pronouncements from professional medical and obstetrics organizations stating that the cesarean rate is too high and cannot be medically justified.1, 9-12 Although there is general agreement that the cesarean rate is too high, there is no agreement on what level it should be.13, 14 There are a number of approaches that have led to recommendations. One approach is to base the recommendation on a country, or part of a country, with a desirable cesarean policy and a comparable population. It is difficult, however, to identify which cesarean rate is desirable. A second approach is to examine the historical cesarean rate records in a country and to select an appropriate level from the past. The difficulty of deciding what is appropriate remains. A third approach is to determine that a certain reduction in rates is possible, on the basis of clinical judgment as to what improve-
From AlgoPlus Consulting Limited. Received for publication December 4, 1998; revised March 17, 1999; accepted April 9, 1999. Reprint requests: Vincent V. Richman, MBA, PhD, AlgoPlus Consulting Limited, 5675 Spring Garden Rd, Suite 502, Halifax, Nova Scotia, Canada B3J 1H1. Copyright © 1999 by Mosby, Inc. 0002-9378/99 $8.00 + 0 6/1/99216
ments in practice are perceived as appropriate. A fourth approach is to select a specific hospital or geographic area where cesarean clinical guidelines are rigorously followed and to use that rate as a national goal. The last 2 approaches particularly rely on professional judgment as to what is medically appropriate. They shed little light on the extent of change in terms of the range and distribution of existing medical practice among hospitals. This article introduces a fifth approach, benchmarking, for the determination of an achievable cesarean rate. Benchmarking determines the target cesarean rate in terms of the distribution of existing practice. Methods The method of benchmarking to analyze cesarean rates does not calculate theoretic optimums15, 16; instead, the performance of similar institutions is analyzed and compared. The minimum standard of accepted performance is assumed to be one point along the diverse range of performance values. The analysis of the distribution of cesarean rates sidesteps the issue of appropriate medical practice and focuses on realistic implementation and achievability. The assigned statistical cesarean rate limits, in these calculations, were rates that constituted the 75th, 50th, and 25th percentiles of Canadian maternity units, although no judgment was made concerning which percentile was appropriate. The underlying assumption was that maternity units that are classified as treating comparable patient populations are expected to have comparable cesarean rates and the performance goal is determined by the existing 635
636 Richman
September 1999 Am J Obstet Gynecol
Table I. Characteristics of maternity unit Cesarean rate distribution
Largest units Intermediate units Smallest units TOTAL
Maternity beds per unit
No. of maternity units
62-127 24-60 10-24 10-127
23 99 117 239
Total maternity beds No.
%
1852 3760 1876 7488
25 50 25 100
Total cesarean deliveries (No.)
25th Percentile (%)
16,487 34,125 10,961 61,573
50th Percentile (%)
75th Percentile (%)
20.4 20.0 18.3 19.3
23.0 22.2 21.8 22.2
19.1 16.9 14.2 15.5
Table II. Impact of benchmarking cesarean rates: Change in numbers of cesarean deliveries Original cesarean deliveries
Largest units Intermediate units Smallest units TOTAL
Rate (%)
No.
20.4 20.2 18.1 19.8
16,487 34,125 10,961 61,573
75th Cesarean rate percentile
50th Cesarean rate percentile
25th Cesarean rate percentile
Assigned norm (%)
Resulting cesareans (No.)
Change in number
Assigned norm (%)
Resulting cesareans (No.)
Change in number
Assigned norm (%)
Resulting cesareans (No.)
Change in number
23.0 22.2 21.8
16,243 32,169 10,454 58,866
–244 –1956 –507 –2707
20.4 20.0 18.3
15,500 30,885 9,620 56,005
–987 –3240 –1341 –5568
19.1 16.9 14.2
14,849 27,658 8,048 50,555
–1,638 –6,467 –2,913 –11,018
distribution of medical practice. Benchmarks were established for each of the 3 size categories of maternity units, the largest, intermediate-sized, and smallest units. The data were obtained from Statistics Canada. All Canadian hospitals are required to complete the Annual Return of Health Care Facilities—Hospitals, the form from which these data are derived.17 The study examines data from 1988-1989, the year of the highest number of cesarean deliveries. The study analyzed the 239 hospitals that had at least 10 maternity beds throughout 19831992. The cesarean delivery rate was calculated by dividing the number of cesarean deliveries by the number of newborn infants. The results from dividing by the number of maternity admissions were similar. The maternity units were classified on the basis of maternity unit size. The largest units were expected to have the most resources for treating patients with more complex conditions, whereas the smallest units were expected to treat those with less complex conditions. The 239 maternity units were stratified on the basis of size into 3 size classes. The purpose of this stratification was to establish separate benchmarks for each class. The largest and smallest maternity units containing 25% of the study group’s maternity unit beds were assigned to the largest and smallest maternity unit category (Table I). Three estimates were calculated by successively setting the 75th, 50th, and 25th percentiles within each maternity unit classification as the assigned statistical cesarean
rate limit. For the purposes of the calculation, maternity units with higher cesarean rates than the assigned statistical cesarean rate limit were set to the assigned rate limit. Those maternity units with lower cesarean rates did not have their cesarean rates changed. Results The 239 hospitals delivered 310,464 neonates and performed 61,573 cesarean deliveries. These totals accounted for 82% of all newborn infants and 85% of all cesarean deliveries in Canada during 1988-1989. The cesarean rate medians were similar for the 3 maternity unit categories. The interquartile differences increased when there were more units within a category. Table I describes the characteristics and distributions of cesarean rates for each of the largest, intermediatesized, and smallest maternity unit categories, as well as for the total 239 maternity units. Table II lists the results from setting the assigned statistical cesarean rate limit within each category at the 75th, 50th, and 25th percentiles, including the resulting cesarean rates, the numbers of cesarean deliveries, and the numbers of fewer cesarean deliveries for each category and overall. Comment The benchmarking method brings 5 advantages to the analysis of medical practice patterns. First, the focus is on the existing distribution of rates. Second, the method is easy to implement and requires no professional judgment. Third, the specific maternity units that need to
Richman 637
Volume 181, Number 3 Am J Obstet Gynecol
change are identified. Fourth, the change in the number of cesarean deliveries at each maternity unit is calculated. Finally, the method is generalizable to all practice patterns. The first advantage of focusing on the existing distribution of performance brings any recommendations into the realm of practicality. The emphasis on explicitly stating that maternity units with rates above a specified percentile should change their rates highlights the practicality and feasibility of the recommendation. The second advantage is the ease of implementation. Target rates are explicitly determined in terms of the percentage of maternity units that should change their rates. The exclusive focus on the distribution of rates removes the need for professional knowledge or judgment. This removes the need for consensus statements or agreements about practice guidelines. The third advantage is that the specific maternity units that need to change are identified. The knowledge of both the numbers of maternity units that should change their rates and the amount of that change provides a perspective on the ease and practicality of achieving the recommended goal. The fourth advantage is that the effect on the numbers of cesarean deliveries at each maternity unit is calculated. The resulting decrease in cesarean deliveries is the combined effect of the number of deliveries and the magnitude of the rate change. When there are limited resources available for intervention efforts to effect change, it is useful to identify maternity units where there is the largest potential effect, the largest potential decreases in cesarean deliveries. The final advantage is one of generalizability. Benchmarking can be applied to the analysis of other procedures—obstetric and nonobstetric, surgical and nonsurgical. The only requirement is that there be wide variation in the application of clinical judgment and, consequently, diversity in practice rates. Benchmarking assumes that there is a reasonable classification process for determining comparable maternity units that treat comparable patient populations. This information was implied by the maternity unit size. The biggest and smallest maternity units had similar cesarean rate medians. Because the medians were similar, there is little basis for concern about whether the classification of the size of the unit was accurate. Benchmarking is a statistical process; it does not indicate which cesarean rate is ideal or safe. The selection of
the 75th, 50th, and 25th percentiles followed conventional practice in using quartiles; other percentiles could have been used. The assistance of Statistics Canada in providing the data is appreciated. REFERENCES
1. Consensus Development Conference on Cesarean Childbirth, September 1980, sponsored by the National Institute of Child Health and Human Development. Bethesda (MD): National Institutes of Health; 1981. Publication No.: 82-2067. 2. Sakala C. Medically unnecessary cesarean section births: introduction to a symposium. Soc Sci Med 1993;37:1177-98. 3. Centers for Disease Control and Prevention, National Center for Health Statistics, Office of Vital and Health Statistics Systems. Rates of cesarean delivery—United States, 1991. MMWR Morb Mortal Wkly Rep 1993;42:285-9. 4. Centers for Disease Control and Prevention, National Center for Health Statistics, Office of Vital and Health Statistics Systems. Rates of cesarean delivery—United States, 1993. MMWR Morb Mortal Wkly Rep 1995;44:303-7. 5. Nair C. Trends in cesarean section deliveries in Canada. Health Rep 1991;3:259-79. 6. Millar W, Nair C, Wadhera S. Declining cesarean section rates: a continuing trend? Health Rep 1996;6:17-24. 7. Placek P, Taffel S. Recent patterns in cesarean delivery in the United States. Obstet Gynecol Clin North Am 1988;15:607-27. 8. American Hospital Association. AHA hospital statistics: the AHA profile of United States hospitals. 1993-94 ed. Chicago: The Association; 1993. 9. American College of Obstetricians and Gynecologists. Guidelines for vaginal delivery after a cesarean childbirth. Statement of the Committee on Obstetrics: Maternal and Fetal Medicine. Washington: The College; 1982. 10. American College of Obstetricians and Gynecologists, Committee on Obstetrics: Maternal and Fetal Medicine. Guidelines for vaginal delivery after a previous cesarean childbirth. Washington: The College; 1984 Nov. 11. American College of Obstetricians and Gynecologists, Committee on Obstetrics: Maternal and Fetal Medicine. Guidelines for vaginal delivery after a previous cesarean birth. Washington: The College; 1988. 12. Society of Obstetricians and Gynaecologists of Canada, Panel of the National Consensus Conference on Aspects of Cesarean Births. Indications for cesarean sections: final statement of the Panel of the National Consensus Conference on Aspects of Cesarean Birth. Can Med Assoc J 1986;134:1348-52. 13. Helewa M. Cesarean sections in Canada: what constitutes an appropriate rate? J Soc Obstet Gynaecol Can 1995;17:237-46. 14. Flamm BL, Quilligan EJ, editors. Cesarean section: guidelines for appropriate utilization. New York: Springer-Verlag; 1995. 15. Garrison RH, Noreen EW, Chesley GR, Carroll RF. Managerial accounting: concepts for planning, control, decision making. Fourth Canadian edition. Toronto: McGraw-Hill Ryerson; 1998. 16. Horngren CT, Foster G, Datar SM, Teall HD. Cost accounting: a managerial emphasis. First Canadian edition. Scarborough (Ontario, Canada): Prentice Hall Canada; 1997. 17. Statistics Canada. 1991. Hospital annual statistics 1988-89. Volume 1: beds and patient movement. Health Rep (Suppl 20) 1991:3(4).