The Component Projection Approach II was originally proposed by Lee and Isbister (1966) to estimate the impact of birth control programmes on fertility. A detailed account of this method is given in United Nations Manual IX (United Nations, 1979:63-75). This method uses service statistics for the estimation of family planning acceptors and the effect of levels of family planning use on fertility. The method is used to estimate the number of births averted in year t by taking into account the number of effective users from 1 April of year t - 1 to 1 April of year t. Since there is an interval of nine months between conception and birth, births prevented in year t result from the practice of family planning between 1 April of year t - 1 and 1 April of year t. In view of the data available, the method is applied to estimate the number of births averted in Pakistan by family planning programme efforts in 1985. The estimates of births averted have been derived from service statistics from 1976 to 1984. The methodology requires information on the number of acceptors by age, method continuation rates and potential fertility. The number of births averted by couples or women in age group i is estimated as the product of:
Qi.tgi where:
Qj,t = number of effective users at the ith age group in year t practicing contraception from 1 April of year t - 1 to 1 April of year t;
gj = potential fertility of acceptors in the absence of the programme; i = successive age groups of users.
The method implies a number of assumptions, that is (a) acceptance occurs at a constant rate throughout each year of the programme so that, on average, each acceptor who does not discontinue remains in the programme for a period of 6 months during the year of acceptance; (b) the number of users as of 1 October (mid-point) of year t - 1 represents the average number of users between 1 April t - 1 and 1 April of year t; (c)
acceptors as of 1 October in the year t - 1 remain in the programme for an average of 4.5 months (mid-point of nine months, 1 January - 30 September); (d) the mortality of users between 1 April of year t - 1 and 1 April of year t is considered negligible; and (e) acceptors are distributed evenly among all ages within age groups (United Nations,
1979: 63-64).
As the service statistics did not provide data on the age distribution of users, the age distribution of users for each method was obtained from the Pakistan Contraceptive Prevalence Survey 1984-85 (Appendix 5.7). This distribution was assigned to users throughout the observation period. This is a reasonable assumption in a situation where the mean age of use did not change significantly over time as evident in the findings of the Pakistan Fertility Survey 1975 and the Pakistan Contraceptive Prevalence Survey
1984-85.
In this analysis, five methods, that is, IUD, pills, condoms, injections and sterilization have been included to ascertain the programme impact. The analysis does not include any of the traditional methods because the programme does not offer those methods. The marital age specific fertility rates obtained from the Population Growth Estimation Survey, 1963-1965, were taken as potential fertility to estimate the number of births averted by each method (Appendix 5.4). These marital fertility rates observed prior to the initiation of a nationwide family planning programme are considered appropriate potential fertility rates as also documented by previous studies (Syed, 1981; Rukanuddin et al., 1985; Sultan, 1987).
The programme data on the number of clinical methods used and conventional contraceptives distributed through family welfare centres, reproductive health centres, clinics, programme personnel, and district distribution points (shops and stores) have been utilized for estimation of births averted by programme effort (Appendix 5.8). From the programme data, numbers of acceptors by each method, year and age were derived on the assumptions that (a) one sterilization = one acceptor, (b) one IUD insertion = one acceptor; (c) 13 cycles of pills = one acceptor; (d) 100 condoms = one acceptor; (e) four injections = one acceptor (Appendix 5.9). From acceptors, the numbers of effective
users by year and method controlling for age were derived (Appendix 5.10) by using the following continuation rate for each method:
Sterilization =1.00 Pills = 0.6
Condoms = 0.6 Injection = 0.45 IUD = R(t) = ae'rt
where R(t) = retention rate at time t; a = constant (0.8444) that allows for immediate expulsion; e = natural logarithm base; and r = a constant (0.0347) which measures the rate of discontinuation.
The assumptions for deriving the number of acceptors from programme statistics and subsequently continuation rates used for calculating effective users from acceptors for each method have been obtained from relevant studies for Pakistan (Syed, 1981; Rukanuddin et al., 1985; Sultan, 1987).
An estimation equation (United Nations, 1979:67-69) was employed to obtain the adjusted ages of IUD acceptors from age groups (from 1976 to 1984) as of October 1,
1984: Qi 1985 = 0.925qi, 1984 + 0.075qi - 1, 1984 + 0.75qi, 1983 + 0.25qi - 1, 1983 + 0.55qi, 1982 + 0.45qi - 1, 1982 + 0.35qi, 1981 +0.65qi- 1, 1981 + 0.15qi, 1980 + 0.85qi - 1, 1980 + 0.95qi, 1979 + 0.05qi - 1, 1979 + 0.75qi, 1978 + 0.25qi - 1, 1978 + 0.55qi, 1977 + 0.45qi - 1, 1977 + 0.35qi, 1976 + 0.65qi - 1, 1976
For deriving survivors of sterilization acceptors, after P months, the five-year survivorship ratios of the United Nations South Asian mortality pattern (United Nations, 1982), with an expectation of life at 53 years for females and 54 years for males were
used. Sterilization acceptors were estimated for 1 October in the year of acceptance by applying these survivorship ratios. Using the same procedure as for IUDs, shifts in ages of sterilization acceptors were adjusted by allowing one-fifth of the acceptors to move to the next age group every 12 months.
A considerable proportion of condoms is likely to be wasted in Pakistan (Planning Commission, 1976; Syed, 1981; Rukanuddin et al., 1985). In this study it is assumed that 75 per cent of condoms are wasted. Therefore estimates for condom users were adjusted accordingly. A similar assumption on the wastage of condoms in Pakistan was made by previous researchers (Rukanuddin et al., 1985).
The estimated number of women protected against pregnancy, that is effective users each year from 1976 to 1984 by age and each method by age, is presented in Appendix 5.10. Using the potential fertility of effective users, the number of births averted through each year and method, by age group of users, was estimated (Table 5.8). The results yield an estimate of 493548 births averted by the programme in 1985. Yearwise births averted from 1976 to 1984 are shown in panel A of Table 5.8. It is evident that the greatest number of births averted occurred in 1976 followed by 1984. The programme activities during 1976 were pushed by previous years of accelerated activities followed by a sudden fall in 1977. During 1977, the political disturbances and change in government might have affected the programme performance. The Islamization campaign also affected the programme performance in the early 1980s, although the programme started picking up again in 1984. Panel B of Table 5.8 indicates that in 1985 the highest number of births (211479) were averted by use of condoms followed by the pill, IUD, sterilization and injection.
The total number of births averted in 1985 estimated using the Component Projection Approach II is higher than the estimates obtained through the standardization technique. One weakness of the Component Projection Approach II is that it uses data pertaining to contraceptive methods in units, reported in service statistics, rather than the number of acceptors of contraceptives. The distribution of contraceptives, especially condoms, which averted more births than other methods even after making allowance
for wastage, does not mean that they were all actually used. This method also assumes 100 per cent use-effectiveness for all methods, which may lead to some overestimation of the effect of contraceptive methods. Hence the estimates of the number of acceptors and effective users derived by the programme assumptions might overestimate the number of births averted.
Table 5.8: Number of births averted by year and method controlling for age, Pakistan
Year/ Method
Age Groups (years)
<25 25-29 30-34 35-39 40+ 15-49 A. B y Y ea1- 1976 23672 23616 21650 16620 6745 92303 1977 9263 10696 9422 7155 2833 39369 1978 12424 14644 13078 9917 3978 54041 1979 20559 21697 20540 15521 6462 84779 1980 7112 7332 7945 6599 2735 31723 1981 1862 2911 4117 3550 1600 14040 1982 6050 9941 10528 8528 3678 38725 1983 8489 14640 14518 11042 5045 53734 1984 12289 24131 22904 16859 8651 84834 B; By Method 09851 IUD 3269 14906 15238 9322 6860 49595 Pill 62244 34087 39470 29891 13809 179501 Condoms 33488 74469 52211 38618 12693 211479 Injections 2366 2027 2815 2124 662 9995 Sterilization 351 4118 14968 15836 7705 42978 Total (1985) 101718 129607 124702 95791 41729 493548
Note: Births averted are calculated by multiplying potential fertility rates by the number of effective users of each method in each age group.
Source: Appendices 5.4 and 5.10.
Table 5.9 compares the estimated current use of various methods derived on the basis of service statistics with those obtained from the Pakistan Contraceptive Prevalence Survey 1984-85. On the basis of service statistics, the estimated current use of all methods by currently married women aged 15-49 years during 1985 amounts to 13.6 per cent compared to 9.1 per cent reported in the Pakistan Contraceptive Prevalence Survey 1984-85. Reported figures of injection and sterilization in service statistics are lower than reported in the Pakistan Contraceptive Prevalence Survey 1984-
85, while those for IUD, pill and condoms are higher in the service statistics. This suggests that there is either an under-reporting of certain methods like condoms and pills in the Pakistan Contraceptive Prevalence Survey 1984-85 or over-reporting in the service statistics.
Table 5.9: Percentage of current contraceptives users by method and source, Pakistan 1984-85
Methods
IUD Pill Condom Injection Sterilization All Methods
PCPS 1984-85 0.8 1.4 2.2 0.6 2.6 9.1*
Survey statistics 1.5 4.8 5.5 0.3 1.5 13.6**
Notes: PCPS= Pakistan Contraceptive Prevalence Survey 1985-85. *= Also includes 1.5 % traditional methods.
**= Estimated from family planning service statistics.
Source: Pakistan Contraceptive Prevalence Survey 1984-85, original analysis of data; Table 5.8 and Appendix 5.10.
Due to the use of family planning methods according to the service statistics of the family planning programme, there was a 13.2 per cent decline in marital fertility during the period 1976-1985 (Table 5.10). The greatest decline was observed in the age group 35-39 years followed by the age group 30-34 years.
Table 5.10: Estimates of effective users, births averted and age-specific marital fertility rate, Pakistan, 1985
Age Potential CMW Effective Births Total Esti- Birth
fertility users averted expec- dmate de-
(000) ted ASMFR cline
births (000) (%) <25 362 3373811 280989 101718 1221320 332 8.3 25-29 350 2620058 370305 129607 917020 301 14.0 30-34 332 2367643 375609 124702 786058 279 16.0 35-39 233 2205621 411122 95791 513910 190 18.5 40+ 89 3491140 468849 41728 310712 77 13.5 Total 9.1 14058273 1906057 493356 3749020 7.9 13.2
Notes: CMW - Currently married women aged 15-49 years. ASMFR - Age specific marital fertility rate.