Abstract
OBJECTIVE
To examine family physicians’ practice of, attitudes toward, and knowledge about maternal serum screening (MSS) and to compare the demographic and practice characteristics, attitudes, and knowledge of physicians who offer MSS to all their pregnant patients with those of physicians who offer MSS to some or none of their pregnant patients.
DESIGN
Cross-sectional mailed survey.
SETTING
Newfoundland and Labrador.
PARTICIPANTS
One hundred eighty-two family physicians who provided prenatal care.
MAIN OUTCOME MEASURES
Proportion of physicians offering MSS to their pregnant patients. Sociodemographic characteristics and attitudes toward and knowledge about MSS of physicians who offer MSS to all, some, or none of their pregnant patients.
RESULTS
Just over half the physicians (52.2%) offered MSS to all their pregnant patients, 34.6% offered it to some patients, and 13.2% did not offer MSS at all. Almost two thirds of physicians (63.6%) had not changed their practice regarding MSS in the past 18 months, but 29.5% said they offered MSS more often. About 69.6% of physicians communicated positive results to patients within 48 hours; 60.8% communicated negative results at the next clinical appointment. Half (50.6%) believed that offering MSS did not affect their legal risk, 24.1% said it increased their risk, and 25.3% said it decreased their risk. Most physicians (83.4%) ordered MSS at the correct gestational age. A larger proportion of those who offered MSS to all patients were female, were between 30 and 39 years old, had graduated from Canadian medical schools, practised in urban centres, and were aware of the provincial MSS program. Physicians who offered MSS to all, some, or none of their patients were similar in terms of length of practice in Canada, whether they performed deliveries, number of pregnant women they cared for annually, beliefs about MSS and legal risk, and general knowledge of MSS detection rates.
CONCLUSION
More than half the family physicians in Newfoundland and Labrador offered MSS to all their pregnant patients, and another third offered it to some patients. Physicians’ practice was not related to their attitudes toward or knowledge about MSS.
Abstract
OBJECTIF
Examiner les façons de faire, attitudes et connaissances des médecins de famille au sujet du dépistage sérique maternel (DSM) et comparer les caractéristiques démographiques, modes de pratique, attitudes et connaissances de ceux qui offrent le DSM à toutes leur patientes enceintes par rapport à ceux qui l’offrent à certaines ou à aucune d’entre elles.
TYPE D’ÉTUDE
Enquête transversale par la poste.
CONTEXTE
Terre-Neuve-et-Labrador.
PARTICIPANTS
Cent quatre-vingt-deux médecins de famille prodiguant des soins prénataux.
PRINCIPAUX PARAMÈTRES MESURÉS
Proportion des médecins offrant le DSM à leurs patientes enceintes. Attitudes et connaissances au sujet du DSM et caractéristiques sociodémographiques des médecins qui offrent le DSM à toutes, certaines ou aucune de leurs patientes enceintes.
RÉSULTATS
Un peu plus de la moitié (52,2%) des médecins offraient le DSM à toutes leurs patientes enceintes, 34,6% l’offraient à certaines et 13,2% ne l’offraient pas du tout. Près des deux tiers des médecins (63,6%) n’avaient pas changé leur façon de faire concernant le DSM au cours des 18 derniers mois, mais 29,5% disaient offrir cet examen plus souvent. Environ 69,6% des médecins communiquaient un résultat positif à leur patiente en moins de 48 heures; 60,8% communiquaient un résultat négatif à la prochaine rencontre médicale. La moitié (50,6%) estimaient que le fait d’offrir le DSM n’affectait pas leur risque d’ordre légal, 24,1% disaient qu’il l’augmentait tandis que 25,3% disaient qu’il le diminuait. La plupart des médecins (83,4%) prescrivaient le DSM au bon moment de la grossesse. Une forte proportion de ceux qui offraient le DSM à toutes leurs patientes étaient des femmes, avaient entre 30 et 39 ans, étaient diplômés d’une faculté de médecine canadienne, exerçaient en milieu urbain et étaient au courant du programme provincial de DSM. Il n’y avait pas de différence entre les médecins qui offraient le DSM à toutes, certaines ou aucune de leurs patientes quant à leurs années de pratique au Canada, le fait qu’ils fassent ou non des accouchements, le nombre de femmes enceintes suivies chaque année, leurs croyances à propos du DSM et du risque d’ordre légal et leur connaissance générale du taux de détection du DSM.
CONCLUSION
Plus de la moitié des médecins de famille de Terre-Neuve-et-Labrador offraient le DSM à toutes leurs patientes enceintes et un autre tiers l’offraient à certaines d’entre elles. Les façons de faire des médecins n’étaient pas reliées à leurs attitudes ou leurs connaissances au sujet du DSM.
EDITOR’S KEY POINTS.
This survey examines how often family physicians offered maternal serum screening (MSS) to their patients in 2003 in Newfoundland and Labrador.
About 52% of family physicians offered MSS to all their pregnant patients, 35% offered it to some, and 13% did not offer it all. Overall, this was a 23% increase over their rates of offering it in 2000.
Women physicians, those between 30 and 39 years old, graduates of Canadian medical schools, urban physicians, and those aware of the provincial MSS program offered MSS more often.
Despite the increase in rates of offering MSS, only 22% of pregnant patients took the test compared with 48% in Ontario. This could reflect a different value system regarding the test.
POINTS DE REPÈRE DU RÉDACTEUR.
Cette enquête voulait savoir à quelle fréquence les médecins de famille offraient le dépistage sérique maternel (DSM) à leurs patientes en 2003 à Terre-Neuve-et-Labrador.
Environ 52% des médecins de famille offraient le DSM à toutes leurs patientes enceintes, 35% l’offraient à certaines et 13% à aucune. Il s’agit là d’une augmentation globale de 23% par rapport à l’an 2000.
Les médecins féminins, ceux de 30 à 39 ans, les diplômés des facultés de médecine canadiennes, ceux des villes et ceux qui connaissaient le programme provincial de DSM offraient plus souvent le dépistage.
En dépit de l’augmentation du taux d’offre du DSM, seulement 22% des patientes enceintes ont subi le test contre 48% en Ontario. Cela pourrait refléter un système de valeurs différent concernant le test.
Maternal serum screening (MSS), a prenatal test that is done during the second trimester, determines a woman’s risk of carrying a fetus with Down syndrome, trisomy 18, or an open neural tube defect. Doing the test regardless of a woman’s age or medical history means that invasive diagnostic tests, such as amniocentesis, can be offered more selectively to those with positive results of screening and that rates of detecting problems can be increased substantially.1
The Canadian Task Force on the Periodic Health Examination2 and the Society of Obstetricians and Gynaecologists of Canada3 indicate there is fair evidence for offering MSS to all pregnant women. The Provincial Medical Genetics Program of Newfoundland and Labrador (NL) introduced the MSS program at the beginning of 2002. Such screening should be of particular interest to the people of NL because, when the program was introduced, NL had the highest incidence of neural tube defects in Canada (4/1000 births).4
A 2000 survey had found that 47% of general practitioners, family physicians, and obstetricians in NL offered MSS to all pregnant women and another 37% discussed MSS with some women.5 In comparison, 87% of family physicians in Ontario offered MSS to all pregnant women.6
Physicians’ use of MSS is related to sex of physician, volume of deliveries, and (in some provinces) size of community. For example, previous studies have found that more women than men physicians and more physicians who performed a large number of deliveries than those who performed few offered MSS to all patients.5-7 Studies in Manitoba and Ontario found that a larger proportion of urban physicians than rural physicians offered MSS to all patients,7,8 but a previous study in NL had not found this difference.5 These studies also reported that up to 30% of tests were not ordered during the correct time. Although surveys of physicians have found that they know little about MSS (such as detection rates and false-positive rates),5,6 these surveys did not examine the relationship between physicians’ use of MSS and their attitudes toward or knowledge about it. As MSS is the first prenatal genetic screening program in NL, understanding what fosters and impedes its recommended use might assist in implementation of other population-based screening tests in Canada.9
This study examines MSS use and attitudes toward and knowledge about MSS among family physicians in NL. It compares the demographic and practice characteristics, attitudes, and knowledge of physicians who offered MSS to all their pregnant patients with those of physicians who offered it to only some of their patients or to none at all.
METHODS
The Human Investigation Committee of the Faculty of Medicine at Memorial University of Newfoundland in St John’s approved this study. We surveyed all 490 family physicians practising in NL based on a list of eligible physicians taken from the mailing list of the NL Medical Board. Physicians who had not provided prenatal care in the previous year were excluded from the study.
We surveyed physicians between September 23, 2003, and November 13, 2003. To promote a higher response rate, we sent out 3 reminder surveys. The third follow-up survey was hand-delivered to the offices of physicians practising within 1 hour of St John’s; physicians in the rest of NL were contacted by telephone.
For this survey, we adapted the questionnaire used by Carroll et al6 to assess the Ontario MSS program. We shortened the survey and altered some of the questions to better represent the MSS program in NL. The survey was pretested on medical students, graduate students, faculty, genetic counselors, and physicians.
We gathered information on physicians’ sociodemographic characteristics (age, sex, medical school), practice characteristics (community size, years in practice in Canada, number of deliveries performed each year, number of years of providing prenatal care, and number of pregnant women cared for each year), MSS practice (MSS offered to all, some, or no patients; change in MSS practice during last 18 months; and turnaround time for notifying patients of results). The survey also asked about attitudes toward MSS (whether MSS could mislead patients into believing physicians could guarantee healthy babies, whether a first-trimester screening was preferable, and opinions about MSS and legal risk), and knowledge about MSS (awareness of the provincial MSS program, correct time for offering MSS, false-positive and true-positive rates for each genetic disease screened). In an open-ended question, physicians who did not offer MSS to their patients were asked why.
Survey data were analyzed using the Statistical Package for the Social Sciences, version 11.5. For the questions involving knowledge of MSS regarding detection and false-positive rates, physicians who were within 5% of the correct value were considered to have chosen the “correct” rate.
Frequencies were used to describe the characteristics of the sample as a whole. Chi-square and t tests were used to identify differences between physicians who offered MSS to all patients, some patients, or no patients. Level of significance was set at <.05. Because all family physicians in the province were sampled, we did not calculate sample size. Frequencies were used to analyze responses from categorized open-ended questions, such as those asking about reasons for not offering MSS.
RESULTS
Among the 490 physicians on the NL Medical Board mailing list, 35 had retired or moved. Of the remaining 455 physicians, 270 responded to the survey for a response rate of 59.3%. Eighty-eight respondents had not provided prenatal care during the previous 12 months and were excluded from the study. This paper reports on the remaining 182 physicians.
To assess the representativeness of our sample, we compared the sex, specialty, and location of practice of respondents with those of physicians on the list provided by the NL Medical Board. We found no significant differences between respondents and nonrespondents.
Table 1 presents characteristics of the physicians in the study and Table 2 characteristics of how they practise. There were more men than women. The largest proportion of respondents (34.3%) were 40 to 49 years old, and 73.6% had graduated from Canadian medical schools. Almost equal proportions of physicians practised in rural and urban settings.
Table 1. Characteristics of respondents.
N = 182.
*Not all physicians answered all questions. Percentages are based on number responding.
Table 2. Characteristics of respondents’practices.
N = 182.
Most respondents (86.8%) offered MSS (52.2% to all and 34.6% to some of their pregnant patients); 13.2% did not offer it (Table 3). About 63.6% of physicians had not changed their practice regarding MSS during the past 18 months; 29.5% said they offered MSS more often. Half of the physicians believed that MSS did not affect their legal risk; one quarter thought it decreased their risk; and one quarter thought it increased their risk. One third of physicians believed that MSS misled patients into believing that physicians could guarantee healthy babies, and more than two thirds said they preferred screening during the first trimester rather than the second trimester. Most physicians (80.4%) were aware of the provincial MSS program, but only 42.5% knew the correct false-positive rate of the test. Few knew the correct detection rates of the test for Down syndrome (17.8%), open neural tube defects (40.5%), and trisomy 18 (36.7).
Table 3.
Practice regarding, attitudes toward, and knowledge about MSS
MSS—maternal serum screening.
*Not all physicians answered all questions. Percentages are based on number responding.
Physicians who offered MSS to only some patients targeted women older than 35, women with a family history of Down syndrome or neural tube defects, and women who requested MSS (Table 4). Most physicians offering MSS (to either some or all of their patients) ordered the test at the correct gestational age, communicated positive results to patients within 48 hours, and communicated negative results at the next clinical appointment.
Table 4.
Practices regarding MSS of physicians who offer it to all or some of their pregnant patients
MSS—maternal serum screening.
*Not all physicians answered all questions. Percentages are based on number responding; percentages add to more than 100% because physicians could give more than 1 response.
Table 5 compares the sociodemographic characteristics and attitudes toward and knowledge about MSS of physicians who offered MSS to all, some, or no patients. Table 6 compares physicians’ practice characteristics. Compared with physicians who offered MSS to some or no patients, a larger proportion of those who offered MSS to all patients were female, were between 30 and 39 years old, had graduated from a Canadian medical school, practised in urban settings, and had been providing prenatal care longer. A larger proportion of physicians who offered MSS to all patients, offered it more often than they had 18 months earlier, while the largest proportion of those who offered MSS to some or no patients had not changed their practice patterns regarding MSS during the previous 18 months. More than 90% of physicians who offered MSS to all patients were aware of the provincial MSS program; only 79.7% of physicians who offered MSS to some patients and 33.3% of physicians who did not offer MSS at all were aware of it. Compared with those who offered MSS to all or some patients, a larger proportion of physicians who did not offer MSS knew the correct detection rates of the test for Down syndrome and trisomy 18.
Table 5.
Characteristics of physicians who offered MSS to all, some, or none of their patients
MSS—maternal serum screening.
Table 6.
Practice characteristics and physicians’ offers of MSS screening
MSS—maternal serum screening, SD—standard deviation.
There were no differences between groups in terms of how long they had been practising in Canada, whether they performed deliveries or the number of deliveries they performed each year, the number of pregnant women they cared for annually, their attitudes toward MSS, or their knowledge of the test’s false-positive rate or detection rates for open neural tube defects or trisomy 18. The most common reason for not offering MSS to patients was that physicians were unaware that the test was available, that it created undue anxiety among patients, and that follow-up was difficult to coordinate (Table 7).
Table 7. Reasons for not offering maternal serum screening.
N = 24.
*Adds to more than 100% because physicians could give more than 1 response.
DISCUSSION
In 2003, 86.8% of family physicians surveyed were offering MSS to their patients. This represents an increase of 23.2% since 2000, when the proportion of family physicians offering MSS to their patients was 29%.5 Despite this increase, use of the test remains low; the NL provincial laboratory reported that only 22% of pregnant women were having MSS.9 In contrast, 48% of all pregnant women in Ontario were having MSS.10 These findings suggest that women in NL are reluctant to have the test and highlight the need to better understand what influences women’s decisions to have MSS.
A qualitative study of Ontario mothers found that women identified 3 global areas (personal values, social support, and quality of health information) that influence the decision to have MSS.11 A Dutch study12 found that the most common reasons for women not to have MSS or nuchal translucency (a screening test for chromosomal abnormalities) were because the results of the tests were uncertain and unreliable, the women were not at high risk, and the women would not abort a fetus anyway. The most common reasons for having the tests were because women wanted to know about the health of their babies, the tests did not involve risk, and the women were at increased risk of having children with Down syndrome. We were unable to find Canadian studies that described women’s reasons for choosing to have or not have MSS. Our current research examines these reasons and looks at women’s knowledge of MSS and where they get their information.
More than one third of physicians in the study offered MSS to some patients, such as women older than 35; women with a family history of Down syndrome, open neural tube defects, or trisomy 18; and women who requested MSS. Maternal serum screening is intended to be population-based screening, and risk rates are calculated by comparing analyzed biochemical marker levels with levels typically seen in the general population.6 Hence, it is inappropriate to recommend MSS solely to women in high-risk groups.
Most physicians surveyed (70.8%) said they preferred a first-trimester screening test. Some larger Canadian centres use a combination of first- and second-trimester screening to increase sensitivity and specificity rates. The first-trimester test is not currently available in NL, however. Introduction of a first-trimester test might improve rates of MSS in NL.
Almost 13% of family physicians were not offering MSS to their patients. Slightly more than half those physicians (58.3%) reported that they were unaware the screening test was available in NL. The number of physicians ordering MSS at the correct gestational age had increased; in 2003, 83.4% of physicians ordered MSS between the 15th and 20th gestational week compared with 70.0% in 2000.5 General knowledge about MSS remained low, however, underscoring the need for ongoing education about MSS. Our findings also suggest that physicians’ practice regarding MSS was not related to their specific knowledge about the test’s qualities. It will be important to assess whether scanty knowledge about MSS affects the quality of counseling given to patients and patients’ willingness to be screened.
Limitations
This study is limited by the self-reported nature of the data. Physicians who were familiar with MSS or who practised evidence-based medicine might have been more likely to respond to the survey. Respondents might have given socially acceptable responses rather than reporting their actual practices or opinions.
Conclusion
More than half the family physicians in NL offered MSS to all their pregnant patients. An additional third offered it selectively to some of their patients. Physicians’ practice regarding MSS was not generally related to their attitudes toward or knowledge about MSS.
Levels of evidence.
Level I: At least one properly conducted randomized controlled trial, systematic review, or meta-analysis
Level II: Other comparison trials, non-randomized, cohort, case-control, or epidemiologic studies, and preferably more than one study
Level III: Expert opinion or consensus statements
Biography
Mr Cavanagh teaches in the Faculty of Medicine at Memorial University of Newfoundland in St John’s.
Footnotes
Competing interests: None declared
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