A comparative study of combined and sequential regimens in a rural area.
A comparative study of steroidal contraceptives in combined and sequential regimens was conducted in the rural Indian village of Allahabad to determine acceptability and use-effectiveness. The combination pill, Ovulen (1 mg ethynodiol diacetate and .1 mg mestranol) was distributed to 170 women from January 1968 to March 1969, allowing 15 months of follow-up. 139 women accepted the sequential regimen--Serial 28 (16 tablets of .1 mg ethinylestradiol, 5 tablets of 1 mg megestrol acetate and 1 mg of ethinylestradiol)--from October 1969 to September 1970, allowing 12 months of follow-up. Acceptability was assessed by the extent of participation. The average for the sequential trial (linearly extrapolated for 15 months) was 7.9 months per woman, while the combined trial averaged 10 woman-months. Continuity for the sequential study was lower in almost every age group, and substantially lower among low parity women with literate husbands. Continuity for the combined regimen at 12 months was 59.5% which is significantly higher than that (44.6%) of the sequential trial (z=2.68, p less than .01). In terms of woman-months, incidence of side effects is significantly higher (z=4.70, p less than .01) in the sequential trial (35.31%) than in the combined regimen (26.24%). The most frequent side effects reported for sequential use were dizziness and breakthrough bleeding. Combined trial acceptors complained of vaginal discomfort. Contraceptive failure rate for the sequential trial (9) was significantly higher than that for the combined regimen (.7) per 100 woman-years (z=10.26, p less than .01). Considering rural Indian women's unfamiliarity with modern drugs, use-effectiveness and acceptability is greater for the combined regimen of steroidal contraception.