Trends in health inequalities in Canadian adolescents from 2002 to 2018

Findings from the 2018 Health Behaviour of School-aged Children (HBSC) Study.

On this page

• Introduction
• Characteristics of the study sample
• Socioeconomic differences in six health domains
• Gender differences in six health domains
• Trends in prevalence and inequalities in adolescent health
• Limitations
• Conclusions
• Methods
• References
• Acknowledgements

Introduction

Social patterns in health track strongly from childhood and adolescence into adulthood (Patton et al., 2016). Therefore, trends in adolescent health inequalities between genders and socioeconomic groups may foreshadow future health inequalities in the adult population.

Despite rising wealth and greater scientific evidence of systemic differences in population health, little progress has been made globally towards the goal of reducing health inequality (Mackenbach, 2012). Data from the Health Behaviour in School-aged Children (HBSC) study show that inequalities in some domains of adolescent health have widened between socioeconomic groups in international populations (Elgar et al., 2015) and gender groups in Canadian populations (Gariépy and Elgar 2016), resembling similar trends found in adult populations (Hu et al., 2016; Mackenbach et al., 2015; Shahidi et al., 2018).

The Canadian HBSC study provides a long view of these trends on nationally representative samples of adolescents in multiple health domains. This report describes trends in socioeconomic and gender inequalities in six domains of adolescent health measured in five consecutive survey cycles (2002 to 2018):

• physical activity
• excess body weight
• frequent physical symptoms
• frequent psychological symptoms
• low life satisfaction
• fair or poor self-rated health

Characteristics of the study sample

There was a decline in two-parent households from 2002 (84.9%) to 2014 (78.0%). Although still lower than 2002, there was an increase in two-parent households noted from 2014 to 2018 (81.3%).

The prevalence of excess body weight increased from 2002 (19.7%) to 2014 (25.1%). Although still higher than 2002, there was a decrease in excess body weight noted from 2014 to 2018 (23.0%).

Across the survey years, adolescents in 2002 had the lowest prevalence of psychological symptoms, low life satisfaction, and fair or poor health with increases reported in the following survey years.

Socioeconomic differences in six health domains

Socioeconomic differences were found in five health domains, with adolescents at the lowest level of material deprivation (i.e., highest socioeconomic status) experiencing more physical activity, less excess body weight, fewer psychological symptoms, less low life satisfaction, and less fair or poor health as compared to adolescents at the highest level of material deprivation. The prevalence of physical symptoms did not differ between socioeconomic groups.

From 2002 to 2018, differences in health between socioeconomic groups increased in four domains - in excess body weight, physical symptoms, low life satisfaction and fair or poor health. In each case, the absolute difference in prevalence between the highest and lowest socioeconomic groups increased. However, relative differences (i.e., rate ratio for the lowest socioeconomic group compared to the highest) were found only in excess body weight. The significance of these trends is summarized in Table 2. Measures of socioeconomic status and health inequality are described in the Methods.

Figure 1: Text equivalent

Physically active

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	25.56%	23.17%	27.95%
	2006	28.51%	26.74%	30.28%
	2010	26.97%	25.51%	28.43%
	2014	28.21%	26.67%	29.74%
	2018	30.44%	28.61%	32.27%
Mean deprivation	2002	21.89%	20.72%	23.07%
	2006	23.25%	22.39%	24.11%
	2010	22.75%	22.02%	23.47%
	2014	23.64%	22.88%	24.40%
	2018	24.35%	23.46%	25.23%
Highest deprivation	2002	18.23%	16.02%	20.44%
	2006	17.99%	16.42%	19.56%
	2010	18.52%	17.16%	19.88%
	2014	19.07%	17.62%	20.53%
	2018	18.25%	16.64%	19.87%

Excess body weight

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	16.24%	13.66%	18.82%
	2006	18.64%	16.74%	20.54%
	2010	17.24%	15.66%	18.83%
	2014	17.99%	16.30%	19.68%
	2018	16.54%	14.53%	18.55%
Mean deprivation	2002	19.69%	18.33%	21.06%
	2006	21.40%	20.43%	22.38%
	2010	21.21%	20.37%	22.06%
	2014	24.98%	24.04%	25.91%
	2018	23.33%	22.22%	24.43%
Highest deprivation	2002	23.15%	20.35%	25.94%
	2006	24.17%	22.12%	26.21%
	2010	25.19%	23.40%	26.98%
	2014	31.96%	29.93%	33.99%
	2018	30.12%	27.70%	32.53%

Two or more physical symptoms

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	26.81%	24.41%	29.22%
	2006	26.81%	25.03%	28.60%
	2010	25.61%	24.19%	27.02%
	2014	25.10%	23.60%	26.59%
	2018	24.15%	22.41%	25.89%
Mean deprivation	2002	25.97%	24.77%	27.18%
	2006	26.91%	26.02%	27.80%
	2010	26.85%	26.11%	27.59%
	2014	25.99%	25.22%	26.75%
	2018	25.94%	25.05%	26.83%
Highest deprivation	2002	25.13%	22.80%	27.46%
	2006	27.01%	25.23%	28.78%
	2010	28.09%	26.59%	29.60%
	2014	26.88%	25.33%	28.42%
	2018	27.74%	25.97%	29.50%

Low life satisfaction

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	9.14%	7.49%	10.78%
	2006	9.83%	8.62%	11.04%
	2010	9.94%	8.91%	10.96%
	2014	9.04%	8.02%	10.06%
	2018	9.70%	8.43%	10.97%
Mean deprivation	2002	14.87%	13.87%	15.88%
	2006	14.90%	14.19%	15.61%
	2010	16.74%	16.11%	17.38%
	2014	16.73%	16.05%	17.40%
	2018	17.02%	16.24%	17.79%
Highest deprivation	2002	20.61%	18.49%	22.72%
	2006	19.97%	18.45%	21.48%
	2010	23.55%	22.19%	24.92%
	2014	24.42%	22.96%	25.87%
	2018	24.33%	22.70%	25.96%

Fair or poor health

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	10.97%	9.29%	12.64%
	2006	10.30%	9.03%	11.58%
	2010	10.92%	9.84%	12.00%
	2014	10.74%	9.67%	11.80%
	2018	11.30%	9.96%	12.65%
Mean deprivation	2002	14.10%	13.15%	15.04%
	2006	15.39%	14.65%	16.12%
	2010	15.64%	15.02%	16.26%
	2014	16.57%	15.91%	17.23%
	2018	16.76%	15.99%	17.52%
Highest deprivation	2002	17.22%	15.29%	19.16%
	2006	20.47%	18.91%	22.02%
	2010	20.37%	19.04%	21.69%
	2014	22.41%	21.00%	23.81%
	2018	22.21%	20.61%	23.81%

Two or more psychological symptoms

Deprivation	Survey cycle	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Lowest deprivation	2002	37.61%	34.82%	40.40%
	2006	38.57%	36.56%	40.58%
	2010	38.39%	36.75%	40.03%
	2014	36.66%	34.94%	38.38%
	2018	40.72%	38.64%	42.81%
Mean deprivation	2002	39.59%	38.20%	40.98%
	2006	41.76%	40.76%	42.77%
	2010	41.65%	40.81%	42.49%
	2014	41.19%	40.31%	42.08%
	2018	44.16%	43.11%	45.21%
Highest deprivation	2002	41.58%	38.80%	44.35%
	2006	44.96%	42.93%	46.99%
	2010	44.91%	43.18%	46.63%
	2014	45.73%	43.90%	47.55%
	2018	47.60%	45.51%	49.69%
Prevalence estimates were weighted and adjusted for gender, age, and family structure. Shaded area represents 95% confidence interval. Socioeconomic status is a regression-based indicator based on a proportional rank in material deprivation. Change in health inequalities over time was tested by regressing each health measure on interactions of deprivation and survey cycle (see Methods). Source: Health Behaviour in School-aged Children (HBSC), Canada, 2002-2018.

Gender differences in six health domains

In all five survey cycles, girls reported experiencing worse health than boys in all domains, except for excess body weight which was more prevalent in boys.

From 2002 to 2018, health differences between gender groups widened in terms of physical symptoms, psychological symptoms, and low life satisfaction. Health differences between gender groups remained stable in physical activity and fair or poor health.

Figure 2: Text equivalent

Physically active

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	26.92%	25.03%	28.81%
	2006	30.64%	29.25%	32.04%
	2010	28.45%	27.32%	29.59%
	2014	30.76%	29.54%	31.99%
	2018	31.17%	29.72%	32.61%
Female	2002	17.04%	15.54%	18.55%
	2006	16.89%	15.84%	17.93%
	2010	17.49%	16.57%	18.42%
	2014	17.48%	16.54%	18.43%
	2018	18.23%	17.12%	19.34%

Excess body weight

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	23.11%	21.02%	25.20%
	2006	25.73%	24.23%	27.23%
	2010	24.72%	23.48%	25.96%
	2014	28.38%	27.00%	29.76%
	2018	25.62%	23.96%	27.27%
Female	2002	16.30%	14.52%	18.07%
	2006	17.43%	16.17%	18.68%
	2010	17.66%	16.53%	18.78%
	2014	21.13%	19.87%	22.38%
	2018	20.24%	18.77%	21.71%

Two or more physical symptoms

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	20.64%	18.97%	22.30%
	2006	20.27%	19.08%	21.46%
	2010	20.07%	19.10%	21.03%
	2014	18.59%	17.62%	19.56%
	2018	17.91%	16.80%	19.03%
Female	2002	30.09%	28.27%	31.92%
	2006	32.80%	31.46%	34.14%
	2010	32.87%	31.72%	34.01%
	2014	32.94%	31.75%	34.12%
	2018	33.69%	32.32%	35.06%

Low life satisfaction

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	12.23%	10.96%	13.51%
	2006	12.34%	11.45%	13.24%
	2010	14.02%	13.22%	14.82%
	2014	12.57%	11.77%	13.38%
	2018	12.20%	11.28%	13.11%
Female	2002	17.17%	15.71%	18.63%
	2006	17.42%	16.37%	18.47%
	2010	18.61%	17.65%	19.57%
	2014	20.34%	19.33%	21.36%
	2018	21.67%	20.50%	22.84%

Fair or poor health

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	12.78%	11.56%	14.00%
	2006	13.02%	12.07%	13.97%
	2010	14.16%	13.34%	14.98%
	2014	14.86%	14.00%	15.72%
	2018	14.84%	13.81%	15.87%
Female	2002	15.73%	14.40%	17.06%
	2006	17.57%	16.50%	18.63%
	2010	16.86%	15.96%	17.76%
	2014	17.74%	16.79%	18.69%
	2018	18.33%	17.23%	19.44%

Two or more psychological symptoms

Gender	Year	Prevalence (%)	95% confidence interval (lower limit)	95% confidence interval (upper limit)
Male	2002	36.27%	34.25%	38.30%
	2006	35.73%	34.29%	37.17%
	2010	34.81%	33.65%	35.98%
	2014	31.74%	30.55%	32.93%
	2018	34.73%	33.28%	36.18%
Female	2002	42.17%	40.21%	44.14%
	2006	47.09%	45.67%	48.51%
	2010	47.74%	46.53%	48.96%
	2014	50.07%	48.80%	51.33%
	2018	52.80%	51.34%	54.27%
Prevalence estimates are weighted and adjusted for socioeconomic status, age and family structure. Shaded area represents 95% confidence interval. Change in health inequalities over time was tested by regressing each health measure on interactions of gender and survey cycle (see Methods). Source: Health Behaviour in School-aged Children (HBSC), Canada, 2002-2018.

Trends in prevalence and inequalities in adolescent health

From 2002 to 2018, the prevalence of ill health increased in four domains. However, the prevalence of daily physical activity rose from 22 to 25 percent. Physical activity is the only health measure that showed no change in inequality between socioeconomic and gender groups over the five survey cycles.

Differences in the prevalence of ill health between socioeconomic groups increased in four domains - excess body weight, physical symptoms, low life satisfaction, and fair or poor health. The largest change was found in excess body weight, where the difference between the highest and lowest socioeconomic groups increased from a 7-point difference in 2002 to a 14-point difference in 2018.

Gender differences in health were stable with respect to daily physical activity and fair or poor health and increased in three domains in both absolute and relative terms: physical symptoms, psychological symptoms, and low life satisfaction. In each case, girls reported poorer health than boys and those gender gaps increased over time.

A decrease in health inequality was found in excess body weight, which decreased in relative terms between gender groups. In 2002, the prevalence of excess body weight in girls was 71% the rate found in boys. In 2018, that figure decreased slightly to 69%.

Limitations

All research studies have limitations and it is important to interpret results in light of their limitations.

1. All data in the HBSC were collected using self-report, which is prone to reporting biases (Choi & Pak, 2005).
2. Socioeconomic status is estimated using an index of material assets that provide or symbolize affluence in the family (e.g., car ownership, vacations). The HBSC Family Affluence Scale is a valid, age-appropriate tool for adolescents, however these data do not correlate closely to household income or parent occupational rank (Elgar et al., 2017). Therefore, the health inequalities reported here may differ from other estimates based on other socioeconomic assessments. Additionally, two items were added to the scale in 2014 and 2018 cycles that were not included in previous cycles. Our use of a proportional rank index (ridit score) to estimate socioeconomic status adjusts for this and harmonizes the variable accordingly.
3. Binary measures of gender (male/female) were used from 2002 to 2014, which excluded and/or misrepresented adolescents who did not identify as either. The 2018 survey allowed for a non-binary response option ("neither term describes me"), as will future cycles.

Conclusions

Five survey cycles of the Canadian HBSC study revealed increased health inequalities between socioeconomic and gender groups from 2002 to 2018.

The burden of ill health shifted towards disadvantaged adolescents in terms of excess body weight, physical symptoms, low life satisfaction, and fair or poor health.

Gender inequalities increased in frequent physical and psychological symptoms and low life satisfaction.

Similar trends were reported in the Canadian adult population (Shahidi et al., 2018) and in adolescents in several European countries (Inchley, 2020).

Monitoring health inequalities in adolescents informs policy approaches to reducing these gaps early in the life course.

Methods

Data source

The data were collected from the 4th to 8th cycles of the Canadian Health Behaviour in School-aged Children (HBSC) study, a World Health Organization cross-national research study that focuses on the health of 11-15 year-old students and was conducted every 4 years.

The main purposes of the HBSC are to understand youth health and well-being and to inform education, health policy and health promotion programs in Canada and abroad (Public Health Agency of Canada, 2020).

Eligible school classrooms across Canada were selected at random and invited to participate in the study. Data were collected in school settings from a nationally representative random two-stage cluster sample of adolescents in grades 6 to 10 from all provinces and territories in Canada.

Measures

Questionnaires included a 6-item measure of material assets in the home (HBSC Family Affluence Scale), which measures number of cars, having one's own bedroom, number of computers in the home, number of bathrooms, family holidays in the past year, and having a dishwasher. The responses were compiled into proportional rank index of material deprivation in the family, ranging from a score of 0 (lowest deprivation) to a score 1 (highest deprivation) with an average of 0.5 (Elgar et al., 2017). Questionnaires also included measures of physical activity (days of 60+ minutes of moderate-to-vigorous physical activity in the previous week), self-reported height and weight, eight psychological and physical symptoms (Gariepy et al., 2016), life satisfaction (Cantril, 1965), and general health (fair, poor, good or excellent).

Statistical analyses

We evaluated differences in health between socioeconomic and gender groups in six health domains. The measure of socioeconomic status (SES) allowed for the computation of regression-based indicators of socioeconomic inequality (Mackenbach & Kunst, 1997). SES was used as an interaction term with the survey cycle to assess for significant trends in socioeconomic inequality over time, while controlling for age, gender, and family structure in multilevel regression models. The gender inequality analysis used gender as an interaction term with the survey cycle to assess for significant trends in gender inequality over time, while controlling for age, SES, and family structure in multilevel regression models. Survey weights were applied to ensure the results were representative of the Canadian population and to equalize the importance of each survey cycle to the analysis. All analyses used standardized weights to account for variations in sampling and a level of significance set at p<0.05, and were conducted in Stata 16.0 (Stata Press, 2019).

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Acknowledgements

• Health Behaviour in School-aged Children (HBSC) is an international study carried out in collaboration with the World Health Organization, European Region (WHO/EURO). The International HBSC Coordinator was Dr. Joanna Inchley (University of Glasgow, Scotland) for the 2017/18 survey and the Data Bank Manager was Dr. Oddrun Samdal (University of Bergen, Norway). The Canadian 2017/18 HBSC survey was funded by the Public Health Agency of Canada, the principal investigators were Drs. John Freeman, William Pickett and Wendy Craig (Queen's University), and the national coordinator was Matthew King (Social Program Evaluation Group, Queen's University).