Quinby PM, Graham AV. Substance abuse among women. Prim Care 1993;20:131-9. 5. MRC Vitamin Study Research Group. Prevention of neural tube defects: ...
Preventing neural tube defects Survey ofpreconceptional use offolic acid leva M. Neimanis, MD, CCFP J. Michael Paterson, MSC Eileen Bain, BSCN, MHSC OBJECTIVE To determine the proportion of women who take daily folic acid supplements in the month before conception and to identify factors associated with supplement use. DESIGN Cross-sectional survey by self-administered questionnaire. SETTING Tertiary care teaching hospital in Hamilton, Ont. PARTICIPANTS Four hundred eighty-four (43%) of 1132 women who delivered normal babies between November 1997 and March 1998. MAIN OUTCOME MEASURES Reports of daily vitamin supplement use in the month before pregnancy and after pregnancy, and having heard or read about the need to take folic acid before pregnancy; sources of information about folic acid; factors associated with preconceptional vitamin use. RESULTS Thirty-four percent of respondents reported taking vitamins before conception (use ranged from 21% for those with unplanned pregnancies to 40% for those with planned pregnancies); 80% after conception. Of all respondents, 63% were aware of the need for preconceptional folic acid. Key information sources were family doctors and the mass media: the media were more important before conception, doctors after. Being older (30 years or more), having post-secondary education, and having a planned pregnancy were associated with knowing about the benefits of folic acid; knowledge, regular exercise, perceived good health, and planned pregnancy were associated with preconceptional use of vitamins. CONCLUSIONS Even in this sample of well educated, English-speaking women, only one third took vitamin supplements before conception, which indicates that current educational efforts do not reach most women early enough. A coordinated, multi-pronged strategy that targets and involves physicians and capitalizes on opportunities to work with schools, public health outlets, and the media is needed. OBJECTIF Determiner la proportion de femmes qui prennent quotidiennement des supplements d'acide folique durant le mois precedant la conception et identifier les facteurs associes 'a l'utilisation de ce supplement. CONCEPTION Une enquete transversale au moyen d'un questionnaire 'a remplir soi-meme. MILIEU Un h6pital d'enseignement de soins tertiaires a Hamilton, en Ontario. PARTICIPANTES Sur 1132 femmes ayant accouche d'un enfant normal entre novembre 1997 et mars 1998, un total de 484 femmes (43%). PRINCIPALES MESURES DES RESULTATS Les rapports sur l'utilisation quotidienne de supplements durant le mois precedant la grossesse et apres la grossesse, ainsi que sur le fait d'avoir lu ou entendu parler 'a propos de la necessite de prendre de l'acide folique avant la grossesse; les sources d'information a propos de l'acide folique; les facteurs associes 'a la prise de vitamines avant la conception. RESULATS Un total de 34% des repondantes ont dit avoir pris des vitamines avant la conception (lutilisation variait entre 21% chez celles dont la grossesse n'etait pas planifiee 'a 40% chez celles dont la grossesse etait planifiee); 80% d'entre elles en prenaient apres la conception. De toutes les repondantes, 63% etaient au courant de la necessite de prendre de l'acide folique avant la conception. Au nombre des principales sources d'information figuraient les medecins de famille et les grands medias. Les medias occupaient une place plus importante 'a ce chapitre avant la conception et les medecins, apres. fttre plus Agees (plus de 30 ans), avoir une education postsecondaire et une grossesse planifiee etaient des facteurs associes 'a la connaissance des avantages de l'acide folique; les connaissances, l'activite physique reguliere, une bonne sante apparente et la grossesse planifiee etaient liees 'a l'utilisation preconceptionnelle de vitamines. CONCLUSIONS Meme dans cet echantillonnage de femmes anglophones bien eduquees, seulement le tiers d'entre elles ont pris des supplements de vitamines avant la conception, ce qui indique que les efforts d'education ne rejoignent pas assez t6t la majorite des femmes. II est necessaire d'avoir une strategie coordonnee, a multiples facettes, qui cible les medecins et comporte leur participation, et qui mise sur les possibilites de travailler avec les ecoles, les centres de sante publique et les medias.
This article has been peer reviewed. Cet article a fait l'objet d'une evaluation externe. Can Fam Physician 1999;45:1717-1722. -*-
FOR PRESCRIBING INFORMATION SEE PAGE 1808
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eural tube defects (NTDs), such as anencephaly and spina bifida, are the most common serious neurologic malformations that affect Canadian infants. About 800 babies (0.1%) are affected each year. The rate varies substantially by region, increasing from 0.16% in British Columbia and Alberta to as high as 0.4% in Quebec and Newfoundland",2 (similar to rates for fetal alcohol syndrome and effects at 0.1% to 0.3%3'4). Sequelae of severe NTDs lead to lifelong physical, social, emotional, and financial difficulties. Fortunately, a large number of NTDs are preventable. Studies have shown that periconceptional folic acid supplementation reduces the risk of NTDs by at least 50% for a first occurrence and by up to 70% for subsequent occurrences.5'6 This evidence has led expert panels, professional associations, and government agencies across Canada and abroad to promote the message that women of childbearing age should be taking daily folic acid supplements. Despite a range of educational initiatives, including development and dissemination of Canadian clinical practice guidelines,7 a well-publicized national conference,8 and local public health campaigns, several studies suggest the message is not getting through to doctors9 or to their patients.1'O- Surveys of Canadian women have shown that few take vitamin supplements before conception.17-` Two of these surveys, however, were of special populations (women whose infants were being treated for spina bifida, and women attending a medical genetics clinic), and all three were too small to identify factors associated with supplement use, factors that might help target future research or educational interventions. We set out to determine how many women giving birth at an Ontario teaching hospital knew about and took folic acid before conception and to identify factors associated with this knowledge and use.
Hospital in Hamilton, Ont. All women who delivered normal babies during the study period and could read English were eligible to participate. Women who delivered babies that had fetal abnormalities or required intensive care were excluded from the study to avoid causing them additional anxiety. A self-administered questionnaire was distributed to eligible women by a ward clerk when they were admitted to the postpartum unit. Completed forms were collected by staff before discharge. We chose this approach rather than a mailed survey because it was convenient (ie, a process was already established for distributing and collecting questionnaires); we could identify and track those with language barriers; and, given the existing infrastructure, it was less costly than a mailed survey.
Survey instrument To help reduce potential bias, neither hospital staff nor subjects were fully apprised of our study objectives, and our primary research questions about folic acid were couched among questions about a range of other preventive health behaviours. Called the "Healthy Lifestyles Questionnaire," the instrument was divided into three parts. Section one described the general purpose of the study and listed conditions for participation. Section two included questions about smoking, drinking, eating, and exercise habits before and during pregnancy, and asked women to assess their own health status. It also questioned women about their use and knowledge of folic acid, in that order. Questions were as follows. * Did you take vitamin supplements on a daily basis in the month before you became pregnant with this
baby? (yes/no) * If yes, did the vitamins contain folic acid?
(yes/no/don't know)
METHODS Setting and subjects This cross-sectional survey was carried out between November 1, 1997, and March 31, 1998, at St Joseph's
* Did you take vitamin supplements on a daily basis after you learned you were pregnant with this
baby? (yes/no) * Have you heard or read anything about the idea of taking folic acid or folate before getting pregnant?
(yes/no) Dr Ne'inanis is an Assistant Clinical Professor in the Department ofFamily Medicine at McMaster University and ah active member of the Department ofFamily Medicine at StJoseph's Hospital in Hamilton, Ont. Mr Paterson is a Research Officer with the Department of Family Medicine and Ms Bain is a Nurse Manager with the Maternal Newborn Program at St Joseph's Hospital.
* If yes, where did you learn about folic acid, and what was recommended? (open response)
Finally, section three of the questionnaire asked about age; level of education; other children; whether or not current pregnancy was planned (ie, "you stopped using birth control or other precautions with
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the specific aim of getting pregnant"); and, if planned, whether women discussed the intended pregnancy with their family doctors before getting pregnant. Our assessment of women's use and knowledge of folic acid was based on their responses to the first and fourth questions, respectively. We chose to ask them about use of "vitamin supplements" rather than folic acid for two reasons: we were concerned that they would not know whether their vitamin supplements contained folic acid, and we knew that most currently available multivitamin preparations do."3 Adding the second question to the survey allowed us to identify the proportion of women who were certain their supplements contained folic acid. Other variables were included in the questionnaire because they either had been,14-16 or we suspected they might be, associated with knowledge or use of folic acid. The final survey instrument was not formally pilottested, but did include input from a committee of six family physicians and the hospital's eight-member ethics review board.
RESULTS Characteristics of respondents Of the 1510 women who delivered babies during the study, 1132 (75%) met the inclusion criteria and were approached to participate. Among those excluded, 214 (14%) were perceived to have language barriers, and the remaining 164 (11%) had babies that were admitted to the neonatal intensive care unit. A total of 484 questionnaires were returned, for a response rate of 43%. Of the 484, 37 questionnaires (8%) were unusable, leaving a final sample size of 447. Respondents' characteristics are shown in Table 1. Mean age was 28.6 (SD ± 5.7) years. On average, they had received 13.9 (SD±3.0) years of formal schooling, and just over 50% had at least some post-secondary education. Although almost 70% of pregnancies were planned, just one third of
Table 1. Characteristics of respondents CHARACTERISTIC
N (%)
Age (y)
Sample size and data analysis Based on earlier research,'2"14'15 we hypothesized that no less than 15% of women whose pregnancies were planned would report having taken vitamin supplements daily before conception. Accordingly, we aimed for a sample size that would allow us to detect this proportion with reasonable confidence. Assuming an unplanned pregnancy rate of 50%,9' we determined that 400 subjects would be needed to detect a 15% proportion within five percentage points with 95% confidence.'8 Univariate statistics (including proportions and 95% confidence intervals [CI] for categorical data and means and standard deviations [SD] for continuous data) were used to portray characteristics of respondents. Tests for differences were conducted using x2 or Fisher's exact tests, as appropriate, for proportions and Student's t test for means. All hypothesis tests were two sided, with type I error (a) set at 0.05. Stepwise multiple logistic regression analysis was used to assess whether factors identified through univariate analyses were associated with women's knowledge and use of folic acid. Only factors that met a significance level of P3 drinks/wk) * Before pregnancy * During pregnancy Daily vitamin supplement use * In month before pregnancy * During pregnancy Knowledge of folic acid (heard or read about need to take before conception) Children (other) Pregnancy planned * Stopped using birth control or other precautions with aim of getting pregnant * Discussed plans with family doctor
36 (8.1) 198 (44.4) 210 (47.0) 3 (0.7)
231 (51.6) 334 (74.7)
418 (93.5)
159 (35.5)
147 (32.9) 97 (21.7)
16 (3.6) 4 (0.9) 154 (34.4) 357 (79.9)
.......................................................................................................
280 (62.5)
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243 (54.4) 310 (69.4) 153 (34.2)
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Peengnrl** tubdeect Preventing neural tube defects
respondents discussed these plans with their family doctors before conception. Most women (75%) perceived themselves to be in "excellent" or "very good" health, and watched their diet and alcohol consumption carefully during pregnancy. A troubling 22% of respondents, however, continued to smoke while pregnant. Based on data from Statistics Canada and the 1990 Ontario Health Survey, our study subjects were generally better educated and healthier than the general population of women of childbearing age in the Hamilton area."9
Factors associated with knowledge and use of folic acid At the time they completed our questionnaire, 63% of respondents were aware of the need to take folic acid before conception. Just 34% actually did so, however: 21% of those whose pregnancies were unplanned and 40% of those whose were not. After pregnancy, supplement use rose to 80%.
Table 2. Factors associated with women's knowledge of folic acid on multiple logistic regression analysis PARAMETER ESTIMATE
STANDARD ERROR
P
-1.447
0.350
