SESSION IV. NATURAL FAMILY PLANNING USE-EFFECTIVENESS AND CONTINUATION Robert T. Kambic, Chair Suzanne Parenteau-Carreau, Rapporteur
Natural family planning use-effectiveness and continuation Robert T. Kambic, MSH Baltimore, Maryland Numerous studies have been conducted to assess the use-effectiveness of natural family planning. noncomparable However, because of imprecise definitions of terms, these studies show noncom parable results. Special effort is required to study natural family planning use-effectiveness by the same criteria as other family OBSTET GVNECOL 1991 ;165:2046-8.) planning methods. (AM J OSSTET
Key words: Natural family planning, use-effectiveness, pregnancy rates
Any method of fertility control, natural family planning (NFP) included, has two major purposes; at the personal level it enables couples to have the number of children they choose, and at the aggregate level it moderates population growth so that the community, the common good, will benefit. To help couples plan their families, service programs must be able to communicate accurate information on how and how well a method can be used. Civil and medical authorities need to have confidence that the family planning methods they recommend will help their populace achieve better health. Thus science has a responsibility to measure effectiveness, continuation, and other family planning evaluation parameters as accurately and reliably as possible. This has been done in large part for medical contraception but is only beginning for NFP. Studying NFP use-effectiveness
There is a 10- to IS-year time lag between NFP evaluation and evaluation of other family planning methods. Tietze Tietze' cites 10 studies on tubal sterilization, 36 studies on oral contraceptives, and other studies on the intrauterine device and barrier methods, virtually all published in the mid to late 1960s. Many of these were studies of thousands of women. Tietze also cites two basal body temperature studies published in 1967 and 1968 with 17,500 and 5000 cycles, respectively. In contrast, the first large trial of the symptothermal method was the Rice study, which was first reported in 1977 with 1022 women 22 ; the first large trial of the ovulation method, the World Health Organization study, published initial results in 1981.3 This time lag benefits NFP From the Department of Population Dynamics, School of Hygiene and Public Health, The Johns Hopkins University. Reprint requests: Robert T. Kambic, MSH, The Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205. 6/0/34195
2046
to the extent that it adapts the refined methodologies of family planning evaluation for its own use. It has hindered NFP because a lack of knowledge about the efficacy has up to now relegated NFP to a subordinate role in family planning. When adapting family planning evaluation methodology for NFP application, knowledge about data collection, results generalization, statistical approaches, and developed-developing country comparisons can be transferred directly to NFP. However, there are other issues that only NFP research can resolve, e.g., the study population in NFP has to be precisely defined. Does a client enter the study at registration, when she is taught, when she begins to chart, or after she has charted for 1, I, 2, or more months? Definition of the study population is especially important to determine early dropout rates. Another example is the study unit: is it the woman or the couple? The woman charts her symptoms but assuming monogamy, both partners abstain. When considering pregnancies occurring in NFP users, there are two approaches: approaches : the accepted practice is to define a pregnancy according to the stated family planning intention of the client before a pregnancy occurs. An alternative practice recommended by some is to classify pregnancies according to the intercourse record of the client during the fertile time of the cycle in which the pregnancy occurred. If intercourse during the fertile time is always indicative of a desire for pregnancies, then unplanned pregnancies are virtually eliminated. In summarizing the 1986 Ottawa conference of the International Federation for Family Life promotion, Dr. Paul Gross, who paraphrased Dr. Ronald Gray said Professor Gray emphasized the dangers of defining these terms in NFP services in a way that does not allow easy comparison with the rates derived from services using other family planning methods. Because NFP will be judged by
NFP use-effectiveness and continuation 2047
Volume 165 Number 6, Part 2
Table I. A decade of NFP effectiveness studies ranked by pregnancy rate; life table rates are cumulative net pregnancies at 1I year or 13 cycles per 100 women. (For definitions of life table and Pearl rates, see aI., which immediately follows.) follows .) Labbok et ai., Country
Reference
Yr
Indonesia Liberia Korea Nepal Zambia Indonesia Kenya United States Philippines Korea Bangladesh Ireland India Colombia Colombia United States El EI Salvador New Zealand India Germany United Kingdom Italy China
7 8 9 10 8 7 11 II 12 3 II 11 11 II 3 3 13 13 12 3 3 14 15 IS 16 17 18
1990 1990 1989 1986 1990 1990 1988 1981 1981 1988 1988 1981 1981 1980 1980 1981 1981 1981 1991 1991 1991 1986 1990
Method
OM
ST / OM ST/OM
OM MMM
ST / OM ST/OM
MMM OM ST OM OM OM OM OM ST OM OM OM OM MMM ST ST ST OM
Life table
2.5 4.3 7.0 7.3 8.9 10.3 10.5 11.2 12.8 13.4 14.9 17.4 17.5 19.1 19.1 22.2 22.4 26.9 27.9
Pearl index
2.0 2.3 2.7 3.7 4.4
OM, Ovulation methods; MMM, modified mucus method; ST, symptothermal method.
such comparisons, those dangers outweigh the advantages and leave the NFP movement open to unnecessary criticism.' criticism: Of special interest are the simplified methods. It is not that people cannot use the standard NFP methods, but the simplified methods are less technical, easier to learn, and in some cases are literally being developed "in the field" by independent users (users not associated with an NFP program). Sociologists know that new, helpful knowledge will spread throughout a community by diffusion, that is, neighbors telling neighbors. NFP simplified methods may be currently undergoing diffusion and are important to a substantial proportion of couples in countries such as Mauritius, the Philippines, and Indonesia.
Communicating results The most precise scientific results in the world are not helpful unless we use them. As Carl Djerassi5 pointed out, a crisis exists in the field of contraceptive development that has provided an opportunity for a fresh look at NFP. To take advantage of this opportunity, the results of effectiveness studies in NFP should be provided to those who will make use of them. them . Table I lists NFP life table and Pearl index effectiveness studies reported during the past decade. Because of the methodology problems in measuring use-effectiveness, the data are not strictly comparable. (For a detailed discussion of the problems of comparing life table rates among studies and methodology problems in family planning evaluation, see Trussell and Kost6 ).
However, an examination of the life table rates in Table I is informative in several ways. There is a factor of about 10 between the lowest reported pregnancy rate of 2.5 and the highestrate highest rate of 27.9. Both are ovulation method studies. The median is 13.1. Of the life table studies with pregnancy rates higher than the median, most were completed early in the 1980s. Of the studies with pregnancy rates lower than the median, all but one were completed after 1988. This suggests that throughout the 1980s, NFP programs improved their service, which enabled clients to achieve better effectiveness. This trend should be monitored. When the Pearl index studies are included in the meta-analysis, we see a diverse group of countries at different levels of development where NFP services are sufficiently established to undertake a study of effectiveness rates. These countries are favorable sites for continued research and program improvement. The articles presented in this section represent examples both of effectiveness studies and factors that impact on NFP effectiveness and continuation. They discuss a variety of approaches,to approaches ,to these issues, reveal past methodologic errors, and provide information on NFP efficacy. REFERENCES 1. Tietze C. Ranking of contraceptive methods by levels of effectiveness. In: Advances in Planned Parenthood, vol VI. Proceedings of the Eighth Annual Meeting of the American Association of Planned Parenthood Physicians, Boston, Massachusetts, April 1970. 2. Rice Fj, Lanctot CA, Garcia-Devesa C. 2. C. The effectiveness
Kambic
3. 4.
5. 6. 7.
8.
9. 10.
of the sympto-thermal method of natural family planning. The Human Life Foundation of America, Washington, DC, 1977. World Health Organization. AA prospective multicenter trial of the ovulation method of natural family planning. II. The effectiveness phase. Fertil Steril1981;86:591-8. Steril 1981;86:591-8. Gross P. Conference summary: presentation on natural family planning. In: Abstracts of Papers Presented at the IV Congress of the International Federation for Family Life Promotion, Serena, Canada, 1986. Djerassi C. Fertility awareness-jet age rhythm method. Science 1990;248:1061-2. Trussell J, Kost K. Contraceptive failure in the United States: a critical review of the literature. Stud Fam Plann 1987;18:237-83. Thapa S, Wonga MV, Lampe PG, Pietojo H, Soejoenoes A. Efficacy of three variations of periodic abstinence for family planning in Indonesia. Stud Fam Plann 1990;21 :327-34. Kambic RT, Gray RH, Lanctot CA, Martin M, Wesley R, Cremins R. Evaluation of natural family planning proZambia. Proceedings of the Congrams in Liberia and Zambia. ference at Georgetown University, Washington, DC, 1991. the .billings ovulation Meng KH, Cho KS. Profile of the. method acceptors and use-effectiveness of the method in Korea. J Korean Med Sci 1989;4:29-34. Schubarth P, Braendlai. Natural family planning: an experience from rural Nepal. Abstracts of papers presented at the IV Congress of the International Federation for Family Life Promotion, Serena, Canada, 1986.
December 1991 Am JJ Obstet Gynecol
11. Labbok MH, Klaus H, Barker D. Factors related to ovulation method efficacy in three programs: Bangladesh, Kenya and Korea. Contraception 1988;6:577-89. 12. Wade ME, McCarthy P, Braustein GD, et al. A randomized prospective study of the use-effectiveness of two methods of natural family planning. AM J OBSTET GYNECOL 1981; 141 :368-76. 13. MedinaJE, Cifuentes A, Abernathy JR, Spieler JM, Wade ME. Comparative evaluation of two methods of natural family planning in Colombia. AM J OBSTET GYNECOL 1980;138:1142-7. 1980; 138: 1142-7. India. Pro14. Dorairaj K. The modified mucus method in India. ceedings of the Conference at Georgetown University, Washington, DC, 1991. 15. Frank-Herrmann P, Freundl G, Baur S, et al. Effectiveness and acceptability of the sympto-thermal method of NFP in Germany. 16. Clubb EM, Pyper CM, Knight]. A pilot study on teaching natural family planning (NFP) in general practice. Proceedings of the Conference at Georgetown University, 1991 . Washington, DC, 1991. 17. Barbato M, Bertolotti G. Natural methods offertility concouples. Abstracts of patrol: trol : aa prospective study of 460 couples. pers presented at the IV Congress of the International Federation for Family Life Promotion, Serea, Canada, 1986. 18. Zhang DW, Xu JX. jX. The effectiveness of the ovulation method used by 688 couples in Shanghai. Shanghai Municipal Family Planning Commission, 1990.
Efficacy studies in natural family planning: Issues and management implications illustrated with data from five studies Miriam H. H . Labbok, MD, MPH,. MPH," Hanna Klaus, MD,b MD: and Alfredo Perez, MDc MDc Washington, D.C., Bethesda, Maryland, and Santiago, Chile Studies of method effectiveness must be carefully assessed for comparability of findings. Several results. This article discusses parameters are identified that are important in the assurance of comparable results. these issues with the use of data from previously published studies and emphasizes the management implications of use-effectiveness data. (AM J OSSTET GVNECOL GVNECOl 1991 ;165:2048-51.) ;165 :2048-51.)
Key words: Natural family planning, use-effectiveness, ovulation method
From the Department of Obstetrics and Gynecology, Georgetown University;a versity;" the Natural Family Planning Center of Washington, D.C., Inc.;b and Pontifica Universidad Catolica de Chile PFDAFAmericas.' Supported by the Agency for International Development, Family Health International, the Institute for International Studies in NatMisereor, and Dr. Alfredo Perez. BRSG supural Family Planning, MisereoT, port was provided by Johns Hopkins University. Reprint requests: Miriam H. Labbok, MD, MPH, MPH, IlSNFP/IRH, IlSNFPIIRH, W ., Washington, DC Georgetown University, 3800 Reservoir Rd., N. W., 20007. 610134196 6/0/34196
2048
Many family planning programs, whether natural family planning (NFP) or others, attempt to gather data to assess the effectiveness of the method(s) they are using. This is a useful effort not only for increasing understanding of the potential impact of the program but also for helping in management decisions. However, these data are not always easily gathered, and the manner of data collection can profoundly affect the outcomes and their comparability. This article discusses issues in use-effectiveness analysis and the applic.ation
Natural family planning use-effectiveness and continuation Robert T. Kambic, MSH Baltimore, Maryland Numerous studies have been conducted to assess the use-effectiveness of natural family planning. noncomparable However, because of imprecise definitions of terms, these studies show noncom parable results. Special effort is required to study natural family planning use-effectiveness by the same criteria as other family OBSTET GVNECOL 1991 ;165:2046-8.) planning methods. (AM J OSSTET
Key words: Natural family planning, use-effectiveness, pregnancy rates
Any method of fertility control, natural family planning (NFP) included, has two major purposes; at the personal level it enables couples to have the number of children they choose, and at the aggregate level it moderates population growth so that the community, the common good, will benefit. To help couples plan their families, service programs must be able to communicate accurate information on how and how well a method can be used. Civil and medical authorities need to have confidence that the family planning methods they recommend will help their populace achieve better health. Thus science has a responsibility to measure effectiveness, continuation, and other family planning evaluation parameters as accurately and reliably as possible. This has been done in large part for medical contraception but is only beginning for NFP. Studying NFP use-effectiveness
There is a 10- to IS-year time lag between NFP evaluation and evaluation of other family planning methods. Tietze Tietze' cites 10 studies on tubal sterilization, 36 studies on oral contraceptives, and other studies on the intrauterine device and barrier methods, virtually all published in the mid to late 1960s. Many of these were studies of thousands of women. Tietze also cites two basal body temperature studies published in 1967 and 1968 with 17,500 and 5000 cycles, respectively. In contrast, the first large trial of the symptothermal method was the Rice study, which was first reported in 1977 with 1022 women 22 ; the first large trial of the ovulation method, the World Health Organization study, published initial results in 1981.3 This time lag benefits NFP From the Department of Population Dynamics, School of Hygiene and Public Health, The Johns Hopkins University. Reprint requests: Robert T. Kambic, MSH, The Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205. 6/0/34195
2046
to the extent that it adapts the refined methodologies of family planning evaluation for its own use. It has hindered NFP because a lack of knowledge about the efficacy has up to now relegated NFP to a subordinate role in family planning. When adapting family planning evaluation methodology for NFP application, knowledge about data collection, results generalization, statistical approaches, and developed-developing country comparisons can be transferred directly to NFP. However, there are other issues that only NFP research can resolve, e.g., the study population in NFP has to be precisely defined. Does a client enter the study at registration, when she is taught, when she begins to chart, or after she has charted for 1, I, 2, or more months? Definition of the study population is especially important to determine early dropout rates. Another example is the study unit: is it the woman or the couple? The woman charts her symptoms but assuming monogamy, both partners abstain. When considering pregnancies occurring in NFP users, there are two approaches: approaches : the accepted practice is to define a pregnancy according to the stated family planning intention of the client before a pregnancy occurs. An alternative practice recommended by some is to classify pregnancies according to the intercourse record of the client during the fertile time of the cycle in which the pregnancy occurred. If intercourse during the fertile time is always indicative of a desire for pregnancies, then unplanned pregnancies are virtually eliminated. In summarizing the 1986 Ottawa conference of the International Federation for Family Life promotion, Dr. Paul Gross, who paraphrased Dr. Ronald Gray said Professor Gray emphasized the dangers of defining these terms in NFP services in a way that does not allow easy comparison with the rates derived from services using other family planning methods. Because NFP will be judged by
NFP use-effectiveness and continuation 2047
Volume 165 Number 6, Part 2
Table I. A decade of NFP effectiveness studies ranked by pregnancy rate; life table rates are cumulative net pregnancies at 1I year or 13 cycles per 100 women. (For definitions of life table and Pearl rates, see aI., which immediately follows.) follows .) Labbok et ai., Country
Reference
Yr
Indonesia Liberia Korea Nepal Zambia Indonesia Kenya United States Philippines Korea Bangladesh Ireland India Colombia Colombia United States El EI Salvador New Zealand India Germany United Kingdom Italy China
7 8 9 10 8 7 11 II 12 3 II 11 11 II 3 3 13 13 12 3 3 14 15 IS 16 17 18
1990 1990 1989 1986 1990 1990 1988 1981 1981 1988 1988 1981 1981 1980 1980 1981 1981 1981 1991 1991 1991 1986 1990
Method
OM
ST / OM ST/OM
OM MMM
ST / OM ST/OM
MMM OM ST OM OM OM OM OM ST OM OM OM OM MMM ST ST ST OM
Life table
2.5 4.3 7.0 7.3 8.9 10.3 10.5 11.2 12.8 13.4 14.9 17.4 17.5 19.1 19.1 22.2 22.4 26.9 27.9
Pearl index
2.0 2.3 2.7 3.7 4.4
OM, Ovulation methods; MMM, modified mucus method; ST, symptothermal method.
such comparisons, those dangers outweigh the advantages and leave the NFP movement open to unnecessary criticism.' criticism: Of special interest are the simplified methods. It is not that people cannot use the standard NFP methods, but the simplified methods are less technical, easier to learn, and in some cases are literally being developed "in the field" by independent users (users not associated with an NFP program). Sociologists know that new, helpful knowledge will spread throughout a community by diffusion, that is, neighbors telling neighbors. NFP simplified methods may be currently undergoing diffusion and are important to a substantial proportion of couples in countries such as Mauritius, the Philippines, and Indonesia.
Communicating results The most precise scientific results in the world are not helpful unless we use them. As Carl Djerassi5 pointed out, a crisis exists in the field of contraceptive development that has provided an opportunity for a fresh look at NFP. To take advantage of this opportunity, the results of effectiveness studies in NFP should be provided to those who will make use of them. them . Table I lists NFP life table and Pearl index effectiveness studies reported during the past decade. Because of the methodology problems in measuring use-effectiveness, the data are not strictly comparable. (For a detailed discussion of the problems of comparing life table rates among studies and methodology problems in family planning evaluation, see Trussell and Kost6 ).
However, an examination of the life table rates in Table I is informative in several ways. There is a factor of about 10 between the lowest reported pregnancy rate of 2.5 and the highestrate highest rate of 27.9. Both are ovulation method studies. The median is 13.1. Of the life table studies with pregnancy rates higher than the median, most were completed early in the 1980s. Of the studies with pregnancy rates lower than the median, all but one were completed after 1988. This suggests that throughout the 1980s, NFP programs improved their service, which enabled clients to achieve better effectiveness. This trend should be monitored. When the Pearl index studies are included in the meta-analysis, we see a diverse group of countries at different levels of development where NFP services are sufficiently established to undertake a study of effectiveness rates. These countries are favorable sites for continued research and program improvement. The articles presented in this section represent examples both of effectiveness studies and factors that impact on NFP effectiveness and continuation. They discuss a variety of approaches,to approaches ,to these issues, reveal past methodologic errors, and provide information on NFP efficacy. REFERENCES 1. Tietze C. Ranking of contraceptive methods by levels of effectiveness. In: Advances in Planned Parenthood, vol VI. Proceedings of the Eighth Annual Meeting of the American Association of Planned Parenthood Physicians, Boston, Massachusetts, April 1970. 2. Rice Fj, Lanctot CA, Garcia-Devesa C. 2. C. The effectiveness
Kambic
3. 4.
5. 6. 7.
8.
9. 10.
of the sympto-thermal method of natural family planning. The Human Life Foundation of America, Washington, DC, 1977. World Health Organization. AA prospective multicenter trial of the ovulation method of natural family planning. II. The effectiveness phase. Fertil Steril1981;86:591-8. Steril 1981;86:591-8. Gross P. Conference summary: presentation on natural family planning. In: Abstracts of Papers Presented at the IV Congress of the International Federation for Family Life Promotion, Serena, Canada, 1986. Djerassi C. Fertility awareness-jet age rhythm method. Science 1990;248:1061-2. Trussell J, Kost K. Contraceptive failure in the United States: a critical review of the literature. Stud Fam Plann 1987;18:237-83. Thapa S, Wonga MV, Lampe PG, Pietojo H, Soejoenoes A. Efficacy of three variations of periodic abstinence for family planning in Indonesia. Stud Fam Plann 1990;21 :327-34. Kambic RT, Gray RH, Lanctot CA, Martin M, Wesley R, Cremins R. Evaluation of natural family planning proZambia. Proceedings of the Congrams in Liberia and Zambia. ference at Georgetown University, Washington, DC, 1991. the .billings ovulation Meng KH, Cho KS. Profile of the. method acceptors and use-effectiveness of the method in Korea. J Korean Med Sci 1989;4:29-34. Schubarth P, Braendlai. Natural family planning: an experience from rural Nepal. Abstracts of papers presented at the IV Congress of the International Federation for Family Life Promotion, Serena, Canada, 1986.
December 1991 Am JJ Obstet Gynecol
11. Labbok MH, Klaus H, Barker D. Factors related to ovulation method efficacy in three programs: Bangladesh, Kenya and Korea. Contraception 1988;6:577-89. 12. Wade ME, McCarthy P, Braustein GD, et al. A randomized prospective study of the use-effectiveness of two methods of natural family planning. AM J OBSTET GYNECOL 1981; 141 :368-76. 13. MedinaJE, Cifuentes A, Abernathy JR, Spieler JM, Wade ME. Comparative evaluation of two methods of natural family planning in Colombia. AM J OBSTET GYNECOL 1980;138:1142-7. 1980; 138: 1142-7. India. Pro14. Dorairaj K. The modified mucus method in India. ceedings of the Conference at Georgetown University, Washington, DC, 1991. 15. Frank-Herrmann P, Freundl G, Baur S, et al. Effectiveness and acceptability of the sympto-thermal method of NFP in Germany. 16. Clubb EM, Pyper CM, Knight]. A pilot study on teaching natural family planning (NFP) in general practice. Proceedings of the Conference at Georgetown University, 1991 . Washington, DC, 1991. 17. Barbato M, Bertolotti G. Natural methods offertility concouples. Abstracts of patrol: trol : aa prospective study of 460 couples. pers presented at the IV Congress of the International Federation for Family Life Promotion, Serea, Canada, 1986. 18. Zhang DW, Xu JX. jX. The effectiveness of the ovulation method used by 688 couples in Shanghai. Shanghai Municipal Family Planning Commission, 1990.
Efficacy studies in natural family planning: Issues and management implications illustrated with data from five studies Miriam H. H . Labbok, MD, MPH,. MPH," Hanna Klaus, MD,b MD: and Alfredo Perez, MDc MDc Washington, D.C., Bethesda, Maryland, and Santiago, Chile Studies of method effectiveness must be carefully assessed for comparability of findings. Several results. This article discusses parameters are identified that are important in the assurance of comparable results. these issues with the use of data from previously published studies and emphasizes the management implications of use-effectiveness data. (AM J OSSTET GVNECOL GVNECOl 1991 ;165:2048-51.) ;165 :2048-51.)
Key words: Natural family planning, use-effectiveness, ovulation method
From the Department of Obstetrics and Gynecology, Georgetown University;a versity;" the Natural Family Planning Center of Washington, D.C., Inc.;b and Pontifica Universidad Catolica de Chile PFDAFAmericas.' Supported by the Agency for International Development, Family Health International, the Institute for International Studies in NatMisereor, and Dr. Alfredo Perez. BRSG supural Family Planning, MisereoT, port was provided by Johns Hopkins University. Reprint requests: Miriam H. Labbok, MD, MPH, MPH, IlSNFP/IRH, IlSNFPIIRH, W ., Washington, DC Georgetown University, 3800 Reservoir Rd., N. W., 20007. 610134196 6/0/34196
2048
Many family planning programs, whether natural family planning (NFP) or others, attempt to gather data to assess the effectiveness of the method(s) they are using. This is a useful effort not only for increasing understanding of the potential impact of the program but also for helping in management decisions. However, these data are not always easily gathered, and the manner of data collection can profoundly affect the outcomes and their comparability. This article discusses issues in use-effectiveness analysis and the applic.ation
