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Does the Type of Provider and the Place of Residence Matter in the Utilization of Prenatal Ultrasonography? Evidence from Canada

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Abstract

Background

There has been a proliferation of repeat prenatal ultrasound examinations per pregnancy in many developed countries over the past 20 years, yet few studies have examined the main determinants of the utilization of prenatal ultrasonography.

Objective

The objective of this study was to examine the influence of the type of provider, place of residence and a wide range of socioeconomic and demographic factors on the frequency of prenatal ultrasounds in Canada, while controlling for maternal risk profiles.

Methods

The study utilized the data set of the Maternity Experience Survey (MES) conducted by Statistics Canada in 2006. Using an appropriate count data regression model, the study assessed the influence of a wide range of socioeconomic, demographic, maternal risk factors and types of provider on the number of prenatal ultrasounds. The regression model was further extended by interacting providers with provinces to assess the differential influence of types of provider on the number of ultrasounds both across and within provinces.

Results

The results suggested that, in addition to maternal risk factors, the number of ultrasounds was also influenced by the type of healthcare provider and geographic regions. Obstetricians/gynaecologists were likely to recommend more ultrasounds than family physicians, midwives and nurse practitioners. Similarly, birthing women who received their care in Ontario were likely to have more ultrasounds than women who received their prenatal care in other provinces/territories. Additional analysis involving interactions between providers and provinces suggested that the inter-provincial variations were particularly more pronounced for family physicians/general practitioners than for obstetricians/gynaecologists. Similarly, the results for intra-provincial variations suggested that compared with obstetricians/gynaecologists, family physicians/GPs ordered fewer ultrasound examinations in Prince Edward Island, British Columbia, Nova Scotia, Alberta and Newfoundland.

Conclusion

After controlling for a number of socioeconomic and demographic factors, as well as maternal risk factors, it was found that the type of provider and the province of prenatal care were statistically significant determinants of the frequency of use of ultrasounds. Additional analysis involving interactions between providers and provinces indicated wide intra- and inter-provincial variations in the use of prenatal ultrasounds. New policy measures are needed at the provincial and federal government levels to achieve more appropriate use of prenatal ultrasonography.

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Notes

  1. In 2005–2006, Canadian hospitals reported an estimated $2.2 billion for the operation of diagnostic imaging services; this was up from the $2.0 billion reported in 2004–2005 [18].

  2. It should be noted here that the numbers of ultrasounds included in the data were those resulting from provider referrals and, as such, they were publicly funded. The data excluded non-referral ultrasounds performed at private diagnostic imaging centres at the request of birthing women. The latter were not publicly funded.

  3. We applied the Poisson finite-mixture model to our data, using two-component Poisson finite-mixture models. The first class (the low-utilization rate group) accounted for 95 % of the sample population, and the second class (the high-utilization group) accounted for only 5 %. Moreover, comparison of the mean and variance of the two components indicated that the first component had a mean of around 2.9, which was close to the overall sample mean. Since the distinction between the two components becomes more blurred or fragile in such cases, we decided not to use this model [30].

  4. In order to compare the performance of various count data models, we used the log-likelihood and AIC and BIC criterion. The model with larger values of log-likelihood and smaller values of AIC and BIC are preferred [30]. The results are available from the authors upon request.

  5. The moments of the numbers of ultrasounds indicates that the distribution was moderately skewed right, with the skewness and kurtosis being 0.65 and 2.60, respectively.

  6. Guidelines in Canada recommend one complete ultrasound in the second trimester (18–20 weeks’ gestation) in a normal pregnancy as a part of routine pregnancy care [33]. Although each province in Canada follows the national clinical guidelines, the administration and delivery of health care services is the responsibility of each province/territory, guided by the provisions of the Canada Health Act [34].

  7. There were a few respondents who were reported to be immigrant and aboriginal. Since the focus was on Canadian Aboriginals, these cases were recorded as immigrants.

  8. Testing for the equality of coefficients on the second and third trimesters indicated that they could be aggregated.

  9. Initially, we created separate dummies for each type of provider. However, testing for the equality of coefficients on provider type indicated that certain types of provider could be aggregated.

  10. Other types of provider (nurses, midwives and others) were not interacted with provinces, because of the small numbers of observations of these providers in some provinces.

  11. The reimbursement rates for different types of provider vary across provinces/territories in Canada. The National Physician Database published by the Canadian Institute of Health information suggests that family physicians, on average, are paid $40.51 per service for total consultation and visits, and that obstetricians/gynaecologists are paid $49.72 per service. However, there are quite a lot of variations across provinces. For family physicians, the costs per service for consultations and visits range from $28.90 in Newfound and Labrador to $54.06 in Alberta, whereas for obstetricians/gynaecologists, they vary from $37.16 in Newfoundland and Labrador to $80.45 in British Colombia [49].

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Acknowledgments

The corresponding author duly acknowledges funding from the Manitoba Research and Data Center for preparation of this article. The authors have no conflict of interest that are directly relevant to the content of the article. The authors would like to thank anonymous reviewers and editor for their invaluable comments and suggestions on an earlier version of this manuscript.

Author contributions

Harminder Guliani contributed to the study design, statistical analysis and preparation of the manuscript; Ardeshir Sepehri contributed to the study design, statistical analysis and review of the results; John Serieux assisted with review and interpretation of the results. All authors made critical revisions of the final manuscript. The corresponding author takes responsibility for the overall content.

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Authors and Affiliations

  1. Department of Economics, University of Regina, Regina, SK, S4S 0A2, Canada

    Harminder Guliani

  2. Department of Economics, University of Manitoba, Winnipeg, MB, R3T 5V5, Canada

    Ardeshir Sepehri & John Serieux

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  1. Harminder Guliani
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Correspondence to Harminder Guliani.

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Guliani, H., Sepehri, A. & Serieux, J. Does the Type of Provider and the Place of Residence Matter in the Utilization of Prenatal Ultrasonography? Evidence from Canada. Appl Health Econ Health Policy 11, 471–484 (2013). https://doi.org/10.1007/s40258-013-0046-9

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