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Several jurisdictions attempting to reform primary care have focused on changes in physician remuneration. The goals of this study were to compare the delivery of preventive services by practices in four primary care funding models and to identify organizational factors associated with superior preventive care.
In a cross-sectional study, we included 137 primary care practices in the province of Ontario (35 fee-for-service practices, 35 with salaried physicians [community health centres], 35 practices in the new capitation model [family health networks] and 32 practices in the established capitation model [health services organizations]). We surveyed 288 family physicians. We reviewed 4108 randomly selected patient charts and assigned prevention scores based on the proportion of eligible preventive manoeuvres delivered for each patient.
A total of 3284 patients were eligible for at least one of six preventive manoeuvres. After adjusting for patient profile and contextual factors, we found that, compared with prevention scores in practices in the new capitation model, scores were significantly lower in fee-for-service practices (β estimate for effect on prevention score = −6.3, 95% confidence interval [CI] −11.9 to −0.6) and practices in the established capitation model (β = −9.1, 95% CI −14.9 to −3.3) but not for those with salaried remuneration (β = −0.8, 95% CI −6.5 to 4.8). After accounting for physician characteristics and organizational structure, the type of funding model was no longer a statistically significant factor. Compared with reference practices, those with at least one female family physician (β = 8.0, 95% CI 4.2 to 11.8), a panel size of fewer than 1600 patients per full-time equivalent family physician (β = 6.8, 95% CI 3.1 to 10.6) and an electronic reminder system (β = 4.6, 95% CI 0.4 to 8.7) had superior prevention scores. The effect of these three factors was largely but not always consistent across the funding models; it was largely consistent across the preventive manoeuvres.
No funding model was clearly associated with superior preventive care. Factors related to physician characteristics and practice structure were stronger predictors of performance. Practices with one or more female physicians, a smaller patient load and an electronic reminder system had superior prevention scores. Our findings raise questions about reform initiatives aimed at increasing patient numbers, but they support the adoption of information technology.
Primary care providers are increasingly interested in ensuring that preventive health care be part of their work routines.1 This reorientation fits with the evidence that recommendations from family practitioners increase substantially the likelihood of patients undergoing preventive manoeuvres,2 whereas the lack of such recommendations has been linked with patient noncompliance.3,4
Studies evaluating adherence to recommended preventive care suggest that the most pervasive barriers rest with the organization of the health care system and the practice itself, such as the absence of external financial incentives for the work done and the lack of a reminder system in the office.3,5–9
Countries attempting to reform their delivery of primary care and improve the delivery of preventive services have often directed their efforts in finding alternatives to the traditional fee-for-service model, in which providers receive payment for each service provided. There are two predominant alternative funding models: capitation (providers receive a fixed lump-sum payment per patient per period, independent of the number of services performed) and salaried remuneration. Some health care systems blend components of fee for service with either of these models or offer additional incentives for reaching defined quality-of-care targets. Despite considerable rhetoric, there is little evidence to point to the remuneration models associated with superior delivery of primary care services.10 The complexity of health care systems makes the evaluation of models through international comparisons difficult.
In Canada, the province of Ontario has four primary care funding models (Table 1). This variety provides a unique opportunity to compare primary care delivery under different funding models in a single jurisdiction. At the time this study was conducted, more than 90% of the provincial population was served by one of the four models. The models vary by funding structure, but also by organizational structure and stated priorities.11
We conducted this study to compare the delivery of preventive services by practices in the four funding models and to identify organizational factors associated with superior preventive care. This study is part of a larger evaluation of primary care models in Ontario funded by the Ontario Ministry of Health and Long-Term Care through its Primary Health Care Transition Fund.
We used a cross-sectional design whereby we conducted chart audits to examine the performance of six preventive manoeuvres in primary care practices in the province of Ontario (Table 2). Data collection took place between October 2005 and June 2006. Details about the methodology of the entire project are reported elsewhere.12
Calculation of the sample size for the main study was based on the ability to detect a difference of 0.5 standard deviation in the disease prevention score (the primary outcome), with an intraclass correlation of 0.2, an α value of 0.05 and β value of 0.20. The recommendation was to sample 40 practices per funding model and 30 patient charts per practice. Because of timing constraints, we had to limit the enrolment to 35 practices per model.
Eligible practices had to have belonged to their funding model for at least one year, provide general primary care services and have at least half of their primary care providers agree to participate in the study. For enrolment, we targeted all 94 practices in the new capitation model (family health networks), the 65 practices in the established capitation model (health services organizations), the 51 practices with salaried physicians (community health centres) and 155 randomly selected traditional and reformed fee-for-service practices that were eligible for this study. We continued to enrol practices until we reached our target of 35 per model or until time precluded further enrolment activity. Recruitment was done through mail invitation, with repeated follow-up using the Dillman method.13
In practices that had paper files, we selected the fifth chart after a predetermined distance until we identified 30 eligible health records. In practices that used electronic records, we used a random-number generator until 30 eligible charts were identified. Eligible patients had to be at least 17 years of age, to be a patient of a participating provider, to have been with the practice at least two years and to have visited the practice in the year before the chart review.12
In each practice, the practice manager or head physician completed an organizational survey that was based on the Primary Care Assessment Tool/Adult Edition14 and was supplemented by additional questions about practice structure. Participating physicians completed a provider survey that captured information about their age, sex, past training and experience. Data from the organizational and physician surveys were used to understand the factors associated with better preventive care.
Chart audits were used to assess the performance of six preventive manoeuvres (Table 2), which were based on recommendations from the Canadian Task Force on Preventive Health Care15 and which had been used in another study.16 For each patient, we calculated an overall prevention score by dividing the number of manoeuvres performed by the number of manoeuvres for which the patient was eligible within the previous 24 months and then multiplying by 100. For example, for a 55-year-old woman eligible for the three cancer screening manoeuvres, her score would be based on the number of cancer screening manoeuvres performed divided by three and multiplied by 100. For a 75-year-old man eligible for the hearing and eye examinations and the influenza vaccination, his score would similarly be calculated as the number of manoeuvres performed divided by three and multiplied by 100.
We compared practice characteristics (patient and physician profiles, contextual factors and organizational structure) across the four funding models using the F statistic (analysis of variance) and the χ2 test, as appropriate. We performed multilevel linear regression analyses to evaluate the bivariate relation between each of these characteristics and the prevention score. Analyses were performed at the individual patient level. We obtained the overall association between each factor and the prevention score for the entire study population while accounting for the clustered nature of the data (patients nested within the provider/practice).
Using multilevel linear regression analyses to account for the clustered nature of the data, we first compared the prevention score (dependent variable) between models of care (main independent variable) unadjusted for other factors. We then adjusted, incrementally, for patient profile and contextual factors, and then physician profile. Because patients were not linked to their providers in the surveys, physician profiles were aggregated to practice-level variables. The addition of successive terms to the analyses sought to uncover the degree to which the differences between funding models could be explained by each of these factors. We retained variables significant at the p < 0.05 level.
To assess whether organizational features of the practices accounted for variation in prevention scores, we continued to build on the analysis by adding variables that captured the organizational features. Again, only variables significant at the p < 0.05 level were retained. To determine the transferability of the results across funding models, we repeated the analysis with the same variables in each of the four models individually. Finally, to determine whether the impact of each organizational feature contained in that analysis was driven by a subset of the preventive manoeuvres, we repeated the analysis using multilevel binary logistic regression analysis in which each preventive manoeuvre was the dependent variable.
The linearity of continuous variables was verified, and where appropriate, the variable was categorized. There were no missing values in the chart data, which captured patient profile and outcome data. Each variable from the surveys contained no more than 3.6% of missing data.17 To avoid case-wise deletion, we imputed missing values of continuous variables using Statistics Canada’s nearest-neighbourhood technique (whereby a missing value for an individual is attributed the value derived from a group of individuals who have a similar profile),18 and we added a separate category for the missing values of a discrete variable for all multivariable regression analyses.
The study design was approved by the Ottawa Hospital Research Ethics Board.
We recruited 35 (23%) of the fee-for-service practices, 35 (37%) of the practices in the new capitation model, 32 (49%) of those in the established capitation model and 35 (69%) of those in the salaried model. Secondary analysis of data from provincial health administrative databases, available for practices in the nonsalaried models only, showed that the physician profile from the participating practices in each of the three nonsalaried models was similar to that of all physicians practising in the respective models in Ontario.12 We abstracted 4108 charts, 3284 of which were for patients eligible for at least one of the six preventive manoeuvres. The prevention score was non–normally distributed across 18 scores; the mean score overall was 61 (range 0 to 100).
After adjusting for patient profile and contextual factors, we found that, compared with the prevention scores in practices in the new capitation model, scores were significantly lower in practices in the fee-for-service and established capitation models but not in practices in the salaried model (Table 5, Analysis B). Practices in the salaried model had scores higher only than those in practices in the established capitation model. After further adjustment for physician factors, only practices in the fee-for-service and established capitation models had prevention scores significantly lower than those in the new capitation model (Table 5, Analysis C).
Three factors not related to patient profile were independently associated with the prevention score (Table 5, Analysis D). When these factors were included in the analysis, the funding model variables were no longer statistically significant. Practices in which we could document the presence of at least one female family physician (based on providers’ responses) had higher prevention scores than practices without a documented female family physician (β estimate of effect on overall prevention score = 8.0, 95% confidence interval [CI] 4.2 to 11.8). Practices with an average panel size (number of patients per full-time equivalent family physician) of fewer than 1600 patients had higher prevention scores than practices with a larger average panel size (β = 6.8, 95% CI 3.1 to 10.6). Finally, practices with an electronic reminder system for recommended patient care (e.g., screening) had higher prevention scores than practices not using such a system (β = 4.6, 95% CI 0.4 to 8.7). The presence of an electronic health record substituted for the reminder system in the analysis conferred about the same effect size (4.6, 95% CI 0.8 to 8.4).
The effect of these three practice-related factors was largely but not always consistent across the funding models (data not shown). The effect was largely consistent across the preventive manoeuvres (Table 6).
We observed important differences in the prevention activities between primary care practices in the four funding models in Ontario. However, when organizational factors were considered, we found that practice structure rather than funding arrangements was the primary determinant of the delivery of evidence-based preventive health care. Across the whole sample, superior prevention scores were associated with the presence of at least one female family physician, a smaller panel size (fewer than 1600 patients per full-time equivalent family physician) and the presence of an electronic reminder system.
The positive effect of female primary care providers on the delivery of preventive care has been reported previously, but it is unclear how this is mediated. Some studies documented a more general positive benefit of female providers on preventive care,19,20 whereas others concluded that sex concordance between patients and their physicians led to better performance of sex-specific preventive manoeuvres among women.21,22 We could not evaluate the effect of sex concordance because physician-specific information was not linked directly to patient data and instead was aggregated at the practice level. However, our finding of a positive association between the presence of one or more female physicians and preventive care was not limited to female-specific manoeuvres, which suggests a more general, cross-cutting effect on preventive care.
We cannot exclude the possibility that features of the practices in which female family physicians chose to practice (other than those available for analysis in the study) were responsible for the higher prevention scores. The presence of a female physician could be ascertained only from the providers’ responses. Because only 50% of providers in a practice were required to participate in the study for the practice to be eligible, some practices that had female physicians who did not participate in the study may have been wrongly classified as not having any female physicians. The effect of this error would be to underestimate the impact of having a female family physician in the practice.
Our finding that busier practices had lower overall prevention scores than practices with smaller patient loads was consistent with findings from other studies in which time constraints, competing demands and opportunity costs were pervasive barriers to quality preventive care.23,24 In Ontario, the standard base capitation rate for a patient is reduced by 50% for additional patients over 2400 enrolled. Our results suggest that the quality of preventive care may be compromised at patient loads below this number. Ontario and other Canadian provinces have a shortage of family physicians, and pressure to meet patient demands with inadequate resources is resulting in ever-increasing patient loads.25,26 Further work is required to establish a benchmark for a patient number that results in better preventive care.
Physicians have reported a need for reminder systems to support their preventive care,3,5 and these tools have been associated with improved care in several studies.7,8,27 We found that the presence of an electronic reminder system was positively associated with prevention scores. We could not determine whether this association was because the system was being used to identify eligible patients for preventive manoeuvres or whether the implementation of information technology indicated practice innovation and an orientation to quality.
Several studies have shown that the lack of financial incentives to support the additional work involved in promoting preventive care is a barrier to improving preventive care.6,9,23,28,29 Several regions have implemented such incentives, but the evidence supporting their impact remains scarce and inconclusive.30,31 In Ontario, incentives to send reminders to patients to obtain preventive care and inducements to achieve greater patient coverage of preventive care have recently been implemented. Practices in each of the two capitation models were eligible for the same incentives during the study period. We could not assess whether these financial inducements affected the likelihood of delivering care. However, because the incentives and the time frame during which they were offered were the same, the incentives alone cannot explain why the prevention score was lower for practices in the established capitation model than for practices in the new capitation model.
The cross-sectional nature of this study allowed us to measure associations but not ascertain causality. We identified three practice-related factors that were independently associated with superior preventive care. However, we could not establish whether these factors led directly to improved care or whether they were a measure of some other feature of the practice that was not captured in the study. The change from fee-for-service payment to capitation funding has been voluntary, and family physicians who chose one model over another may have differed in some way that affected their attention to preventive medicine. This would be a greater concern if we had detected significant differences in preventive care associated with type of funding model after accounting for organizational features of the practices.
As with any study, the extent of data collection is finite. We know from previous studies that the quality of preventive care is associated with attributes of primary care that we could not assess, such as the quality of the patient–provider relationship, the duration and continuity of the relationship,32 the organization’s culture (i.e., the importance or focus it places on preventive care),29 and the providers’ knowledge and beliefs.33 The nearest-neighbour technique used to impute missing values is a single imputation technique that can lead to distorted estimates (if the assumptions on which the imputation is based are flawed) and to inflated precision.34 Finally, we aggregated physician characteristics to the practice level, which probably reduced our ability to detect associations between these factors and preventive care.
No funding model was clearly associated with superior preventive care. Factors related to physician characteristics and practice structure were stronger predictors of performance. Superior prevention scores were associated with the presence of at least one female family physician in the practice, a smaller panel size (fewer than 1600 patients per full-time equivalent physician) and the presence of an electronic reminder system. The fact that these associations were largely consistent across the funding models and across individual preventive manoeuvres supports their relevance to improving the delivery of high-quality primary care services.
Competing interests: Simone Dahrouge was a consultant to the Conference Board of Canada on a study evaluating Family Health Teams in Ontario. No competing interests declared by the other authors.
Disclaimer: John Fletcher is a Deputy Editor for CMAJ. He was not involved in the editorial decision-making process for this article.
This article has been peer reviewed.
Contributors: William Hogg, Laura Muldoon and Betsy Kristjansson conceived the original study with others and oversaw its implementation. They helped with the analysis and participated in the writing of the manuscript. Grant Russell helped oversee the implementation of the project, helped guide the analysis and participated in the writing of the manuscript. Simone Dahrouge was responsible for the quantitative data collection and analysis and oversaw the writing of the manuscript. Robert Geneau participated in the analysis and participated in the writing of the manuscript. Meltem Tuna performed the data analysis and participated in the writing of the manuscript. John Fletcher advised on the analysis and interpretation of the data and participated in drafting and writing the manuscript. All of the authors approved the final version of the manuscript submitted for publication. William Hogg acts as guarantor.
Funding: Funding of the original study on which this research is based was provided by the Primary Health Care Transition Fund of the Ontario Ministry of Health and Long-Term Care. The views expressed in this report are the views of the authors and do not necessarily reflect those of the Ontario Ministry of Health and Long-Term Care.