摘要：Objectives . The reliability of abortion self-reports has raised questions about the general usefulness of surveys in research about abortion behavior; however, the extent of underreporting remains a subject of some debate. This study sought to examine abortion reporting in a sample of welfare mothers and to determine factors in underreporting. Methods . In New Jersey, which covers abortions requested by welfare recipients under its Medicaid program, the responses of a randomly drawn sample of 1236 welfare mothers about abortion events were compared with the Medicaid claims records of these women. Results . Only 29% of actual abortions were self-reported by the women in the sample. This finding varied dramatically by race, with substantially higher rates of underreporting by Blacks than by Whites or Hispanics. Conclusions . Although race is the most consistent predictor of underreporting behavior, attitudinal factors and survey technology also help in explaining abortion reporting behavior. Survey research has become a staple for policy analysts over the past several decades and has always served as a critical data source in the study of many issues of interest to sociologists, demographers, and political scientists. The usefulness of surveys in studying highly personal or sensitive individual characteristics, such as income, crime victimization, mental health, or sexual behavior, however, has been questioned many times. 1– 4 It would be difficult to imagine a more sensitive topic than induced abortion, yet surveys have commonly been used to study abortion behavior. Accurate reporting of induced abortions is important for 2 reasons. First, accurate reports are crucial to estimating the incidence of unintended pregnancies, which is of immense interest to reproductive health professionals and researchers. Data on unintended pregnancies, in turn, are critical to assessing the failure rate of contraceptives and the need for contraceptive services. Underreporting of abortions introduces a downward bias in the estimation of contraceptive failure rates calculated from survey data 5– 7 (also E. F. Jones and J. D. Forrest, unpublished report, 1989). Second, an unreported abortion is also an unreported pregnancy. Demographers rely heavily on pregnancy data to estimate fecundity and elucidate the fertility dynamics of populations. 8, 9 Many studies were undertaken in the 1980s to assess the reliability of survey data on abortions. These studies, however, relied on average or aggregate characteristics culled from external data sources to gauge the quality of survey data. Only 1 previous study has compared self-reported abortion data with external medical records for the same individuals. 10 Three major national surveys have contributed information on abortion at an individual level in recent years: (1) the National Survey of Family Growth, (2) the National Surveys of Young Women, and (3) the National Longitudinal Surveys of Work Experience of Youth. The principal sources of external data used by researchers in assessing the reliability of survey estimates of abortions have been the Alan Guttmacher Institute's provider surveys and the Centers for Disease Control and Prevention's compilation of state health department and other abortion data. Findings on underreporting from various studies show that the rate of underreporting ranges from 40% to 65%; that is, only 35% to 60% of actual abortions are reported in surveys. Previous researchers have identified some factors that influence underreporting of abortions. Udry et al. provide a useful taxonomy that classifies these factors as fertility-related, demographic, or survey implementation factors. 10 Hammerslough adds a further dimension, namely, psychologic repression. 5 Underreporting of abortions has been found to vary with fertility-related factors , such as the method of contraception used and the number of abortions a woman has had. 11, 12 Demographic factors that have been identified as most consistently influencing underreporting of abortions are race and marital status of the respondent. Non-White and unmarried women are significantly more likely than others to underreport. 5, 13, 14 Interviewer characteristics, the directness of the abortion question, and the interview method have also been found to be useful predictors of underreporting. London and Williams found that women of all races are more likely to underreport having had an abortion to an interviewer who is not of their own race. 15 There is some evidence that abortion questions that are asked indirectly—through prefacing, filtering questions, or randomized response technique—result in a higher rate of abortion reporting. 5, 16 In the present study, abortions reported by a sample of New Jersey welfare clients surveyed in 1995 were compared with abortion data on the same individuals from Medicaid claims files. Demographic information for the analysis was drawn from New Jersey public welfare administrative records. Data from these 2 sources, while not perfect, are generally considered the most reliable administrative data available because they are directly linked to welfare check issuance or vendor payments. Both data sources are subject to rigorous internal quality control edits and external sampling audits. It should be pointed out that none of the previous studies that have examined abortion underreporting have included respondents' attitudes toward abortion and, more generally, attitudes toward childbearing experience. In the present study I used a set of 3 scales developed by W. B. Miller (unpublished paper, 1993) that probe these attitudes. Miller's Abortion Attitude Index (AAI) measures the respondent's overall attitude toward abortion and attempts to tap the physical, social, psychologic, and moral aspects of pregnancy termination. The second scale measures the respondent's positive childbearing motivation (PCM), and the third measures negative childbearing motivation (NCM). (The items that constitute the 3 scales are described in an appendix that is available from the author.) I hypothesized that women who have a less restrictive attitude toward abortion would be more likely to report abortions, regardless of demographic, interviewer, or fertility-related factors, and that the same would be true of women with a more negative (less positive) attitude toward childbearing.
