Measuring the extent of abortion underreporting in the 1995 National Survey of Family Growth

Abstract

Context: Induced abortions are often severely underreported in national surveys, hampering the estimation and analysis of unintended pregnancies. To improve the level of abortion reporting, the 1995 National Survey of Family Growth (NSFG) incorporated new interview and self-report procedures, as well as a monetary incentive to respondents.

Methods: The weighted numbers of abortions reported in the main interview of the 1995 NSFG (Cycle 5), in the self-report and in the two procedures combined are compared with abortion estimates from The Alan Guttmacher Institute. The Cycle 5 estimates are also compared with estimates from previous cycles of the NSFG.

Results: The self-report produces better reporting than the main interview, but combining data from the two procedures yields the highest count of abortions. For the period 1991-1994, the level of reporting is 45% in the main interview, 52% in the self-report and 59% when the two methods are combined. The level of abortion reporting in the combined data ranges from 40% for women with an income less than the federal poverty level to more than 75% among women who were older than 35, those who were married at the time of their abortion and those with an income above 200% of the poverty level. The completeness of abortion reporting in the main interview of Cycle 5, though indicating a remarkable improvement over reporting in Cycle 4, is comparable to the levels in Cycles 2 and 3.

Conclusions: The usefulness of the NSFG remains extremely limited for analyses involving unintended pregnancy and abortion.

PIP: This study assessed the extent of full reporting of induced abortion in the 1995 National Survey of Family Growth (NSFG). NSFG has new interview and self-report procedures for correcting undercounts. NSFG Cycles 2-4 were found to record under 50% of abortions that actually occurred in the US. This study compared the level of abortions reported under each of two NSFG survey procedures (the main interview and the self-report). These 2 sources were used to derive the best abortion estimates available from Cycle 5. Estimates from Cycle 5 were compared to earlier cycles for general reporting and for reporting on subgroups of women. Self-reported abortion data appeared to be somewhat less consistent than main interviews and lacked valid dates. The computer entries could increase the potential for input errors. Analysis includes the comparison between: 1) the number of abortions that were reported in the main interview with those that actually occurred in the US; 2) self-reported abortions with external estimates; and 3) both sources of abortions with external estimates. In general, women reported abortions more completely in self-reports during 1976-90. A more complete count occurred with the combined sources. Even with the new procedures in Cycle 5, abortions were undercounted. The combined sources yielded 64% of the actual abortion events. Abortion reporting in the main interview and combined sources varied widely across subgroups. However, for some subgroups, self-reports improved reporting by 33%. Higher level of education was associated with a low accuracy of reporting.