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Knowledge of Periconceptional Folic Acid for the Prevention of Neural Tube Defects
The Missing Links
Miguel M. Bonin, MD, CCFP;
Jennifer A. Bretzlaff, BScN, RN;
Sandra A. Therrien, MA;
Brian H. Rowe, MD, MSc, CCFP(EM);
for the Northeastern Ontario Primary Care Research Group
Arch Fam Med. 1998;7:438-442.
ABSTRACT
Background Periconceptional folic acid supplementation is effective in preventing primary and secondary neural tube defects (NTDs) and other congenital defects. However, debate exists regarding the effectiveness of public and physician education on patient knowledge and compliance.
Objective To examine the level of knowledge about the usefulness of periconceptional folic acid supplementation in a sample of patients from primary care practices.
Design Cross-sectional survey. A confidential, anonymous questionnaire was completed by patients before physician encounters. A maximum of 20 consecutive female patients from each of 3 age groups (16-24, 25-32, and 33-40 years) were recruited from each primary care practice.
Settings Twenty-two Canadian teaching practices affiliated with the Northeastern Ontario Primary Care Research Group.
Outcome Women's knowledge of periconceptional folic acid supplementation for the prevention of NTDs.
Results Of 1125 eligible female patients between the ages of 16 and 40 years visiting their family physician in 1996, 1124 (99.9%) completed the questionnaire. General awareness of NTDs was high (62.7%); however, knowledge that these defects were preventable was lower (22.5%). Only 7.8% of the women made the association between folic acid intake and NTDs. The specific knowledge that NTDs could be prevented with folic acid supplementation before conception was identified by 1.8% of the sample. Pregnant participants were at least twice as likely to be informed about the link. Interpractice variability existed with respect to knowledge of folic acid supplementation.
Conclusion Knowledge of periconceptional folic acid supplementation for the prevention of NTDs was low in this sample and is likely to be reflected in missed opportunities to prevent an important class of congenital malformations.
INTRODUCTION
CLINICAL TRIAL evidence has conclusively demonstrated that periconceptional folic acid supplementation prevents neural tube defects (NTDs).1-3 For primary prevention of NTDs, administration of folic acid, 0.8 mg/d, decreased the rate of all malformations by 42% and NTDs by 100%.3 For secondary prevention, administration of folic acid, 4.0 mg/d, reduced the rate of NTD recurrence by 72%.2 Although the mechanism of this effect is incompletely understood, this evidence has led many organizations4-7 to recommend periconceptional folic acid supplementation to prevent NTDs.
Although increased folic acid intake may be achieved through diet or drug therapy, only drug therapy has been shown to be effective. Some dietary standards recognize the need for increased folic acid during pregnancy and have recommended higher intake levels.8 Also, fortification of foods with folic acid may not occur for many years.9 Consequently, supplementation is the only means to achieve the required folic acid intake at this time.10
Because 95% of births occur in women without high-risk factors (eg, a previous NTD birth, a close relative with a history of NTD birth, lower socioeconomic status, patients being treated for epilepsy, and patients with insulin-dependent diabetes mellitus),11-13 all women capable of conception are encouraged to consume folic acid (0.4 mg) daily at least 1 month before conception and through the first trimester.6-7,10 Women at high risk should receive 4.0 mg/d at least 3 months before conception and through the first trimester.
Women's awareness of the need for periconceptional folic acid supplements, and compliance with recommendations, has not been well studied. In 1 study,11 published before the current guidelines, 14% of women used periconceptional multivitamin supplements. Supplementation rates remain low for all pregnant women in Britain14 and for those with documented NTDs in Canada.15 Persistence of these low rates represents missed opportunities for prevention.
The goal of this study was to survey women of reproductive age in a defined geographic area. This survey measured their level of knowledge regarding periconceptional folic acid supplementation and its role in preventing NTDs.
PATIENTS AND METHODS
DESIGN
A survey was conducted of female patients seen by their family physicians. Packages containing a cover letter and questionnaire were mailed to primary care practice personnel for distribution. Patients completed the questionnaire before physician assessment and returned their voluntary, anonymous, and confidential responses to the receptionist or by mail in a sealed envelope.
NORTHEASTERN ONTARIO PRIMARY CARE RESEARCH GROUP
Primary care practices belonging to the Northeastern Ontario Primary Care Research Group, a group of primary care physicians associated with the Northeastern Ontario Family Medicine Program, University of Ottawa, Sudbury, Ontario, were recruited.
PATIENTS
Patients were approached by primary care practice personnel, who documented the number, acceptance, and ages of all patients. Patients between 16 and 40 years of age who could read French or English and were not obviously unwell were eligible.
QUESTIONNAIRE
Based on a literature review, a 36-item questionnaire was developed. After collecting demographic information, the questionnaire evaluated pregnancy status (complete obstetric history) and knowledge about folic acid supplementation. Family history of NTDs and other known risk factors were determined. Questions also assessed knowledge of preventive issues during pregnancy (smoking, alcohol consumption, and exercise). The questionnaire was self-administered, required less than 15 minutes to complete, and contained no specific references to folic acid. It was entitled the "Women's Reproductive Health Survey," and respondents supplied all answers to questions, ie, options were not provided.
QUESTIONNAIRE TESTING
The questionnaire was field tested by 10 local physicians and later by 20 female patients, resulting in minor modifications. The demographics sections were taken from a previous, well-validated Ontario survey16; the study received ethics approval.
SAMPLE SIZE
Approximately 1000 patients were expected to participate, with equal representation from each of the 3 age groups. This sample was expected to provide estimates of ±1% for primary outcomes.
STATISTICAL CONSIDERATIONS
Analysis was completed using statistical analysis software (SPSS/PC+, SPSS Inc, Chicago, Ill). Continuous data are reported as mean±SD and are analyzed using analysis of variance techniques. Categorical data are reported as number (percentage) and are analyzed using  2 statistics. Repeated testing of a data set reduces the overall  level; therefore, a standard P=.01 was used for statistical significance.
RESULTS
CHARACTERISTICS OF THE PRIMARY CARE PRACTICES
Thirty-one primary care practices agreed to participate; 3 (10%) later withdrew because of logistic difficulties. Of the remaining 28 primary care practices, 22 (79%) returned 30 or more questionnaires and were included in the analysis. During the study, 1 of 1138 patients refused to participate. Age (>40 years) accounted for an additional 13 exclusions (1.1%); 1124 questionnaires comprise the database.
CHARACTERISTICS OF THE STUDY POPULATION
The sample was evenly distributed among the 3 age categories; mean age was 28.6 years (Table 1). Overall, 78% of patients surveyed had seen their family physician at least 2 times in the previous year; the average number of visits was 5.6 per year. One hundred fifty-two patients (13.5%) were pregnant at the time of the survey (Table 1). Fourteen respondents (1.2%) reported a family history of NTDs; 6 previous NTD births had occurred (4.1 per 1000 births).
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Table 1. General Characteristics of 1124 Female Respondents Based on Age*
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KNOWLEDGE OF NTDs AND THEIR PREVENTION
More than half of the respondents (62.7%) were familiar with the term "neural tube defects" (Table 2), and this percentage increased with age (P<.001). Most respondents (77.5% [871]) were unaware that taking medicines or vitamins could prevent birth defects. Only 201 women (17.9%) stated that supplementation with folic acid could prevent NTDs. This knowledge was greatest among 25- to 32-year-olds (Table 2).
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Table 2. Knowledge of Neural Tube Defects (NTDs) and Correct Preventive Use of Periconceptional Folic Acid Supplementation in 1124 Respondents*
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KNOWLEDGE OF FOLIC ACID AND FOLIC ACID SUPPLEMENTATION
Although 116 respondents (10.3%) knew that folic acid supplementation was necessary, fewer understood that it was required for NTD prevention or before conception. Knowledge of the direct link between folic acid supplementation and NTD prevention was indicated by only 88 respondents (7.8%). Moreover, only 20 respondents (1.8%) were aware of the periconceptional requirement for folic acid supplementation.
Pregnant participants were more knowledgeable than nonpregnant respondents in all aspects of the folic acid–NTD prevention link (Table 3). Again, this knowledge was highest among 25- to 32-year-olds and lowest among 16- to 24-year-olds. Women who were pregnant were also more likely to have appropriately taken periconceptional folic acid compared with respondents who were not currently, but had previously been, pregnant (odds ratio, 2.0; 95% confidence interval, 1.2-3.3).
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Table 3. Comparison of the Knowledge of Neural Tube Defects (NTDs) and Their Prevention With Folic Acid Supplementation Between 152 Pregnant and 972 Nonpregnant Respondents
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Interpractice variation was observed with respect to knowledge of periconceptional folic acid supplementation, with a range of 5% to 20% among women in each primary care practice sampled.
COMMENT
This large-scale survey found consistently poor knowledge of the association between periconceptional folic acid intake and NTD prevention in a sample of female patients of reproductive age. Only 18% of respondents could identify the need for this supplementation before pregnancy, and less than 2% knew the reasons for this intake. The group of 16- to 24-year-olds was the least likely to identify these links. These results are disturbing because, for supplementation to succeed, knowledge must exist before planning a pregnancy.
In addition, all age groups in this sample were poorly informed regarding their ability when pregnant to affect fetal outcomes through preventive measures. Only 23% of the sample was aware of the benefits of any medications or vitamin supplementation in pregnancy. Moreover, this knowledge was of a general nature and was not associated with the link between supplementation and prevention of NTDs. Some respondents mentioned the folic acid–NTD prevention link, but few recognized that periconceptional intake was necessary. Although women may not need to understand the rationale for supplementation to benefit, actual compliance may be higher if this link is understood.
Few patients in the sample were attempting to become pregnant (2%); however, fewer than half (44%) were using contraception. This should not be surprising because at least 50% of all pregnancies are unplanned.17 Moreover, because 80% of sexually active couples not using contraception will conceive within a year,18 all sexually active women of reproductive age should consider folic acid supplementation.
Despite these disappointing results, some findings are encouraging. For example, considerable primary care practice variation exists with respect to knowledge; rates ranged from 5% to 20% for the direct knowledge of the folic acid–NTD prevention link. The reasons for this variation deserve further evaluation. In addition, the group of 25- to 32-year-olds consistently demonstrated the highest levels of knowledge. Finally, more than twice as many pregnant compared with nonpregnant respondents could identify this link. Unfortunately, although this may be reassuring, even those who were pregnant demonstrated poor knowledge.
Results of this study indicate that educational information distributed by family physicians has the potential to be influential. For example, most patients were visiting their physicians for reasons other than pregnancy on the survey days. Overall, most patients had seen their family physician at least 2 times in the past year. These results reinforce the role of family physicians in counseling patients about the need to consume folic acid before pregnancy.
Factors associated with high-risk status were infrequently identified in this sample, suggesting that case finding might be an ineffective solution. However, the rate of NTD births in many northern communities and in our sample is high.19 Thus, there is a more urgent need to change the knowledge and behavior of these patients, who seem to be unaware of their risks.
The optimal strategy for improving rates of periconceptional folic acid supplementation has not been determined. A health strategy designed to change these results may need to be multifactorial. First, fortification of foods with folic acid may be an effective intervention.19 Further research into dietary habits and possible benefits of fortification should become a priority.
Second, patient education interventions may be effective, but the efficacy of verbal and visual information (eg, pamphlets and videos) needs further evaluation. Timing of educational interventions may be similarly important, and this also requires further study. In addition, although it is possible that physician education may increase their own knowledge, how this translates into patient knowledge and behavior is not clear. Finally, public education may have a role to play because it may not be sufficient to contact patients directly.
Certain limitations of this study may affect the accuracy of our estimates regarding periconceptional folic acid use. First, this study was conducted in a rural, northern, and remote group of primary care practices. Knowledge of folic acid may be lower in this area than in other regions because rural communities may not be exposed to public education campaigns as commonly.20
Conversely, Northeastern Ontario Primary Care Research Group membership is voluntary for primary care practices associated with this training program. The physicians involved in this program have an expressed interest in research, and their patients may not be similar to other patients, resulting in an overestimation of folic acid knowledge in their patients and in this sample. Finally, patients of physicians with a specific interest in obstetrics may have more awareness of folic acid, resulting in a small overestimation.
However, the strengths of this study are its large sample size, patient anonymity, and the sampling techniques. Sampling nonreferred patients makes generalizations to other settings more reasonable. Finally, the respondents were required to provide all answers (ie, options were not provided) and were unaware of the research interest in folic acid; therefore, the results would not suffer from a social desirability or suggestion bias.21 The results of this study highlight the need to reexamine strategies for improving women's understanding of the link between NTD prevention and periconceptional folic acid intake.
AUTHOR INFORMATION
Accepted for publication July 31, 1997.
Members of the Northeastern Ontario Primary Care Research Group (in order of decreasing patient enrollment) are Michael Franklyn, MD, Sudbury; Dan Krawczuk, MD, Sudbury; Paul Malette, MD, Hanmer; Jean Anawati, MD, Sturgeon Falls; Robert Armstrong, MD, Richard's Landing; Eric Paquette, MD, Timmins; Jim McKay, MD, Espanola; Tom Urban, MD, Sudbury; Frank Chi, MD, Elliot Lake; Craig Hogg, MD, Elliot Lake; Bob Hamilton, MD, and Shelagh McRae, MD, Gore Bay; Tom Crichton, MD, Sudbury; Paul Rheault, MD, Sudbury; Tim Zmijowski, MD, Sudbury; René Laflèche, MD, Hearst; Jane Cox, MD, and Kay Bech-Hansen, MD, Copper Cliff; Roy Jeffery, MD, Little Current; Ed Najgebauer, MD, Sudbury; Ed Gardiner, MD, Kirkland Lake; David Crookston, MD, Sault Ste Marie; Bruce Demers, MD, North Bay; and Andre Morrison, MD, Sturgeon Falls.
This study was supported by research grant 95-58R from the Physicians Services Inc Foundation, Toronto, Ontario.
Presented at the Annual Scientific Assembly for the College of Family Physicians of Ontario, Toronto, November 16, 1996, and at the Annual Scientific Assembly for the College of Family Physicians of Canada, Toronto, May 19, 1997.
We thank the members of the Northeastern Ontario Primary Care Research Group and their staffs who took the time to recruit patients and to encourage them to complete the questionnaires and the patients who gave their time to complete the questionnaires. In addition, we thank Sandra Bennett of the Physicians Services Inc Foundation for her assistance with this project and John Jacono, PhD, Peter Rowe, MD, and Vic Sahai, MSc, for their manuscript review.
Reprints: Brian H. Rowe, MD, Division of Emergency Medicine, University of Alberta, 1G1.63 Walter Mackenzie Centre, 8440-112 St, Edmonton, Alberta, Canada T6G 2B7 (e-mail: brian.rowe{at}ualberta.ca).
From the Department of Family Medicine, Northeastern Ontario Family Medicine Program, University of Ottawa (Dr Bonin), and Sudbury Regional Hospital (Mss Bretzlaff and Therrien), Sudbury, Ontario; and the Division of Emergency Medicine, University of Alberta, Edmonton (Dr Rowe). A complete list of the members of the Northeastern Ontario Primary Care Research Group is given at the end of this article.
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