Understanding adolescent and young adult use of family physician services: a cross-sectional analysis of the Canadian Community Health Survey

Primary health care is known to have positive effects on population health [1] and may reduce at-risk behavior and health problems in adolescence [2]. Yet little is known about the factors that are associated with adolescent and young adult use of family physician services. It is critical to determine the factors associated with use in order to inform effective primary health care policy. This paper addresses this gap in primary health care services research by examining three policy-relevant issues concerning adolescent and young adult use of family physician services: inequity; the unique developmental stage of adolescence; and the distinction between utilization (users versus non-users) and intensity (high users versus low users).

First, the issue of inequity was explored by examining the relationship of access to a regular medical doctor, geographic location, household income, and need, to family physician use. There are studies that look at adolescents' use of all types of physicians: United States [3‐18], Canada [19, 20], and Spain [21]. Many of these are solely descriptive, providing only mean number of visits or proportions of adolescents making visits, sometimes stratifying by age, race, income/insurance. Three of these examined family physician services [8, 16, 19]. None have information about whether adolescents had access to a regular medical doctor, a factor associated with use in adults [22, 23] and important with the current shortage of family physicians, not only in Canada but in many parts of the world [24‐30].

Second, the important developmental differences throughout adolescence and young adulthood were examined. Adolescent and young adult health care is distinct from adult care in that the responsibility for accessing and making decisions concerning care shifts from the parent in younger adolescence to the young adult. Yet often adolescents and young adults are included with children or with adults in research studies [9, 11, 21, 31]. For example, in adulthood, females make more visits than males [31, 32] and a Canadian study of adolescents 12 to 19 years, found that females made more visits for all types of physicians [20]. This study examined if there were sex differences for family physician utilization and whether this varied depending on the age of the adolescent.

Third, the distinction was made between users and non-users (utilization), and among users, between high users and low users (intensity). Health care use has usually been modeled as a count outcome, or as a dichotomy between those who used services and those who did not. Both these classifications assume that the factors associated with use will be the same for non-users, low volume users and high volume users. In fact, there may be factors that distinguish users from non-users, while other factors distinguish high users from low users. Two recent Canadian studies conceptualized adult health care service use as a two level model [31, 32]. However, no adolescent studies were found that conceptualize physician use in this way.

Health care policy and planning should be informed by information that takes into account these important distinctions in adolescent and young adult health care.

A secondary analysis was conducted using the 2005 Canadian Community Health Survey (CCHS)[33]. The CCHS is a multi-stage stratified cluster design, population-based, cross-sectional health survey administered to Canadians 12 years of age and older. For this study, only adolescents and young adults (ages 12 to 24 years) were included. Details regarding the CCHS can be found on the Statistics Canada website [34]. Permission was received from the Statistics Canada Research Data Centre (RDC) to access these data at The University of Western Ontario. Approval from The University of Western Ontario Health Sciences Research Ethics Board was not required because this was a secondary analysis with no possibility of identification of individual survey respondents.

Figure 1 summarizes the inclusion and exclusion criteria. The sample sizes for the analysis were: 12 to 14 year olds - 4985, 15 to 19 year olds - 8718, and 20 to 24 year olds - 6681. Cases included in the analysis were compared to those excluded because of missing data to determine if they varied by age, sex, and province of residence. In early adolescence, there was no difference among the provinces but females and younger early adolescents were more likely to have missing data. In middle adolescence, there was no difference between males and females or among ages but western provinces had more missing cases than eastern provinces. In young adulthood, there were no differences in the amount of missing data for any of sex, age, or province.

Three messages concerning adolescent and young adult use of family physician services, not known previously, are highlighted: 1) inequity concerning access and geography; 2) differences in each sub-group of adolescence and young adulthood; and 3) the important distinction between utilization (users versus non-users) and intensity (high users versus low users).

The first key message concerns the inequitability of family physician services. Two important factors concerning inequity were associated with the use of family physician services - having access to a regular medical doctor and geographic variation. Having a regular medical doctor was highly associated with being a user for all three age groups. This is consistent with the adult literature where having a usual source of care has been related to use of utilization [22, 23]. Conventional wisdom suggests that access to a regular doctor is not important to adolescents because they use school services or health clinics. This finding confirms that access to a regular doctor is as important to adolescents and young adults as it is to adults. The difference in the probability of being a user of family physician services between those with a regular medical doctor and those without was approximately 20%. This difference has significant policy implications with respect to ensuring universal access to primary health care for adolescents and young adults. Also, despite a federal universal health care system, adolescents from Quebec were less likely to use family physician services. A study using the 2001 Canadian Community Health Survey also found variation in utilization by province for adults [32]. This regional variation deserves more attention. However, consistent with equitable access was the finding that the presence of an increasing number of chronic conditions was a strong factor associated with utilization for early and middle adolescence and for intensity of services for all three age groups. As well, household income was for the most part not associated with being a user. This is in contrast to four American studies that found income positively associated with utilization [4, 6, 7, 11]. It is thought that, because of universal access to health care in Canada, income should not be a barrier to receiving care. This appears to be the case for family physician utilization in this dataset.

The second key message is that adolescents are not a homogeneous group. The factors associated with use in the early and middle adolescent groups were in keeping with parental involvement in health care decision-making. The factors associated with use in young adulthood show the emerging independence of this age group. For example, the number of self-perceived need variables associated with intensity of use increased across the age groups. Previous adolescent studies have found a relationship between poorer health status and increased utilization [5, 11, 20, 21]. In the current study, the relationship was not as straight-forward highlighting crucial differences among the three stages of adolescence. Additionally, females were higher users of family physician services starting in middle adolescence and the difference was not totally attributable to contraceptive needs. Health care policy must be sensitive to these developmental distinctions in order to be effective.

The third key message embedded in all the findings is that the factors associated with family physician utilization (users versus non-users) were different than those associated with intensity of use (high users versus low users). Future research must consider this important distinction when modeling health care use. This finding also suggests the necessity to be clear with respect to which outcome (utilization or intensity) health care policy is intended to address. Factors associated with utilization must be understood when considering universal equitable access to primary health care while factors associated with intensity must be understood when considering appropriate use of primary health care resources.

The clearest policy-relevant message that arises out of these findings is the distinctly different stages of adolescence. This can be seen when examining health care policy designed to encourage adoption of vaccinations for sexually transmitted infections (STIs). While efforts to encourage vaccination may successfully be directed to young adults, policies aimed at younger adolescents must consider that parents are still the primary decision-maker for younger adolescents. One study found that parental intent to vaccinate against STIs was significantly associated with adolescents' intent to accept STI vaccination [39]. The controversy that surrounded the uptake of the HPV vaccine was due partly to a lack of understanding regarding the role parents play in young adolescent health care which resulted in not addressing parental concerns about safety and parental autonomy [40].

This study employed the CCHS, a Canada-wide population-based study making it representative of most of the adolescent population. Because it is not possible to measure temporality in a cross-sectional study, it was not possible to determine causal relationships but rather only to report associations between the outcomes and the independent variables. However, many of the variables were not time sensitive; either they did not change (e.g. sex, country of birth) or they were stable over time (self-perceived health). The concern about the cross-sectional nature of the survey is somewhat balanced by the consistency of these variables over time. The variables most sensitive to change over time were the health practices.

Another limitation of the study may be the use of self-report measures. Some studies have found under-reporting of health practice in adolescence while others have not found this to be a large problem [41‐43]. The inconsistent relationship of health practices with utilization may be, in part, due to variables being cross-sectional and based on self-report.

Future research could examine the factors associated with family physician use for specific groups of adolescents and young adults such as those with chronic conditions. Multi-level methods could be employed to examine contextual factors that might elaborate the variation found between geographic areas.

There is limited primary health care services research that examines adolescent and young adult health care use employing multivariate analysis. This understanding of adolescent patterns of utilization, in addition to simply describing them, can inform health care policy that is responsive to this critical developmental stage.