Regional variations in the economic burden attributable to excess weight, physical inactivity and tobacco smoking across British Columbia - HPCDP: Volume 36-5, May 2016

Volume 36 · Number 4 · April 2016

Regional variations in the economic burden attributable to excess weight, physical inactivity and tobacco smoking across British Columbia

H. Krueger, PhDFootnote 1 ,Footnote 2 ; J. M. Koot, BScFootnote 2 ; D. P. Rasali, PhDFootnote 3 ,Footnote 4 ; S. E. Gustin, MPHFootnote 3 ; M. Pennock, MScFootnote 5 

https://doi.org/10.24095/hpcdp.36.4.02

This article has been peer reviewed.

Author references

Correspondence: Hans Krueger, H. Krueger & Associates Inc., 4554 48B Street, Delta, BC V4K 2R8; Tel: 604-946-5464; Email: hans@krueger.ca

Abstract

Introduction: Prevalence rates of excess weight, tobacco smoking and physical inactivity vary substantially by geographical region within British Columbia (B.C.). The purpose of this study is to determine the potential reduction in economic burden in B.C. if all regions in the province achieved prevalence rates of these three risk factors equivalent to those of the region with the lowest rates.

Methods: We used a previously developed approach based on population-attributable fractions to estimate the economic burden associated with the various risk factors. Sex-specific relative risk and age/sex-specific prevalence data was used in the modelling.

Results: The annual economic burden attributable to the three risk factors in B.C. was about $5.6 billion in 2013, with a higher proportion of this total attributable to excess weight ($2.6 billion) than to tobacco smoking ($2.0 billion). While B.C. has lower prevalence rates of the risk factors than any other Canadian province, there is significant variation within the province. If each region in the province were to achieve the best prevalence rates for the three risk factors, then $1.4 billion (24% of the $5.6 billion) in economic burden could be avoided annually.

Conclusion: There are notable disparities in the prevalence of each risk factor across health regions within B.C., which were mirrored in each region's attributable economic burden. A variety of social, environmental and economic factors likely drive some of this geographical variation and these underlying factors should be considered when developing prevention programs.

Keywords: economic burden of disease, populations at risk, risk factors, tobacco smoking, physical activity, body weight

Highlights
  • In British Columbia in 2013, the economic burden due to excess weight ($2.6 billion) was higher than for tobacco smoking ($2.0 billion) or physical inactivity ($1.0 billion).
  • The economic burden of excess weight, physical inactivity and tobacco smoking differs across the 16 health regions in British Columbia.
  • Reducing the prevalence of excess weight, physical inactivity and tobacco smoking in all the health regions to that of the region with the lowest rates would lower the total annual economic burden by one quarter, from $5.6 billion to $4.2 billion.
  • Variation in the prevalence of excess weight, physical inactivity and tobacco smoking is greater within B.C. (24%) than between provinces (10%).
  • The geographical variations between the health regions may help decide which prevention efforts should be directed to which areas.

Introduction

The annual economic burden of excess weight, physical inactivity and tobacco smoking was about $52.8 billion in 2013 in Canada.Reference 1 A modest 1% annual relative reduction in the prevalence of these three risk factors can have a substantial health and economic impact over time at the population level, resulting in an estimated $8.5 billion annual reduction in economic burden in Canada by 2031.Reference 2

With a land mass of almost 10 million square kilometres, Canada is the world's second largest country. The country is divided into 10 provinces and 3 territories. The total population was about 35.2 million in 2013, with the provinces ranging in population from 146 000 in Prince Edward Island to 13.6 million in Ontario.Reference 3 British Columbia (B.C.), the westernmost province, has a population of 4.7 million.

Of all the provinces, the prevalence of tobacco smoking, excess weight and physical inactivity were the lowest in B.C. in 2012. If age- and sex-specific prevalence rates from B.C. were applied to the populations in other provinces, the annual economic burden attributable to these three risk factors would be reduced by $5.3 billion, or 10.0% of the $52.8 billion total economic burden of the risk factors.Reference 1

While B.C. has lower prevalence rates of these risk factors than any other province, there is significant variation within the province. B.C. is divided into five health authorities: Fraser Health, Vancouver Coastal Health, Vancouver Island Health, Interior Health and Northern Health. The health regions range in population from 0.3 million (Northern Health) to 1.7 million (Fraser Health). Each health authority (HA) is further subdivided into three or four health service delivery areas (HSDAs), with a population of between 73 000 (Northeast HSDA) and 748 000 (Fraser South HSDA).

The purpose of our study is to determine the potential reduction in economic burden in B.C. if all HSDAs in the province achieved prevalence rates of excess weight, physical inactivity and tobacco smoking equivalent to those of the HSDAs with the lowest rates.

Methods

Details of our base model, together with an update, have been previously described.Reference 1,Reference 2,Reference 4 Briefly, we used an approach based on population-attributable fraction to estimate the economic burden associated with the three risk factors. This involves the following seven steps:

  1. estimate the prevalence of the three risk factors in the geographical regions of interest;
  2. estimate the causal relationship between the risk factor and comorbidities based on relative risk;
  3. calculate the population-attributable fraction taking into account the continuous nature of excess weight (from no excess weight to overweight to obese) and tobacco smoking (no, light, moderate and heavy smoking);
  4. estimate the direct costs of treating the comorbidities associated with the risk factors in the geographical regions of interest;
  5. adjust the direct costs for overlapping risk factors in a given person;
  6. estimate indirect costs;
  7. disaggregate the total economic burden to provide an estimate of the economic burden of each risk factor.

Prevalence rates for tobacco smoking, overweight/obesity and physical inactivity were drawn from the 2011/12 Canadian Community Health Survey(CCHS). People were considered overweight if their body mass index (BMI) was between 25 kg/m2 and 29.9 kg/m2 and obese if their BMI was equal to or greater than 30 kg/m2, calculated based on self-reported height and weight. For youth aged 12 to 17 years, the Cole system of BMI was used to determine overweight and obesity rates.Reference 5

Tobacco smokers were grouped as light (< 10 cigarettes per day), moderate (10–19 cigarettes per day) and heavy (≥ 20 cigarettes per day) smokers based on the average number of cigarettes smoked per day according to the CCHS 2011/2012 Public Use Microdata File (PUMF).Reference 6 All current smokers who identified themselves as occasional smokers were included in the "light smoking" category.

Physical inactivity rates were based on people categorized as "inactive" in the CCHS. Respondents were classified as active, moderately active or inactive based on an index of average daily leisure time physical activity over the past 3 months. For each leisure time physical activity the respondent engaged in, an average daily energy expenditure was calculated by multiplying the number of times the activity was performed by the average duration of the activity and the estimated energy cost (kilocalories per kilogram of body weight per hour) of the activity. The index was calculated as the sum of the average daily energy expenditures of all activities. Respondents were classified as physically inactive if their leisure energy expenditure was less than 1.5 kcal/kg/day. We made one adjustment to this base CCHS data, namely estimating the rates of overweight, obesity and physical inactivity for children aged younger than 12 years based on the sex-specific rates for 12- to 14-year-olds from the CCHS. We assumed that no children under the age of 12 smoked tobacco.

The sources and values for the relative risks associated with tobacco smoking,Reference 7 excess weightReference 8 and physical inactivityReference 9 remain the same as in the previously published model.Reference 1,Reference 2,Reference 4

Calculating and adjusting costs

We estimated the economic burden (direct and indirect costs) associated with the risk factors in B.C. and each HA/HSDA in the province using a prevalence-based cost-of-illness approach. The cost estimates are expressed in 2013 Canadian dollars.

In our model, direct costs include hospital care, physician services, other health care professionals (excluding dental services), drugs, health research, public health, administration and "other" health care expenditures. In B.C., these costs equal $22.0 billion of the $27.1 billion in total health care expenditures, based on data extracted from the National Health Expenditure Database.Reference 10 Costs excluded from the $27.1 billion were for other institutionsFootnote * ($1.7 billion), dental services ($2.1 billion) and capital ($1.3 billion).

Expenditures within the categories of "other health care professionals" (dental services, vision care services, other) and "other health spending" (research and other) were not detailed for B.C. We assumed a distribution of these expenditures equivalent to the distribution in Canada. To distribute these $27.1 billion to B.C. HAs and HSDAs, we first derived the volume of acute care cases and days by HA and HSDA based on the patient's residence.Reference 11 Thus, we attributed the days spent by a patient in a hospital in another region back to the patient's home region. We then used the distribution of acute care patient days by HA and HSDA to distribute the $8.2 billion in hospital expenditures in B.C. We distributed all other costs to the HAs and HSDAs based on the proportion of hospital costs attributed to that region.

Hospital care, physician care and drug costs by sex were allocated to each comorbidity based on 2008 data from the Economic Burden of Illness in Canada (EBIC) online tool.Reference 12 The comorbidities associated with excess weight include some cancers (esophagus [ICD-10 code C15], colorectal [C18 – 20], pancreas [C25], postmenopausal breast [C50], corpus uteri, including endometrium [C54 – 55], ovary [C56] and kidney [C64]), type 2 diabetes (E11 – 14), hypertension (I10 – 15), ischemic heart disease (I20 – 25), pulmonary embolism (I26), cerebrovascular disease (I60 – 99), asthma (J45), gallbladder disease (K80 – 82), osteoarthritis (M15 – 19) and chronic back pain (M45 – 54). Comorbidities associated with physical inactivity include colorectal cancer (C18 – 20), breast cancer (C50), type 2 diabetes (E11 – 14), hypertension (I10 – 15), ischemic heart disease (I20 – 25), cerebrovascular disease (I60 – 69) and osteoporosis (M80 – 82). Comorbidities associated with tobacco smoking include cancers of the lip, oral cavity, pharynx, larynx [C00 – 14, 30 – 32], esophagus [C15], stomach [C16], colorectal [C18 – 20], liver [C22], pancreas [C25], trachea, bronchus, lung [C33 – 34], kidney [C64] and urinary bladder [C67]) as well as ischemic heart disease (I20 – 25), pulmonary embolism (I26), venous thromboembolism (I80 – 82), cerebrovascular disease (I60 – 69), aortic aneurism (I71), pneumonia (J12 – 18), chronic lung disease (J40 – 44), intestinal ischemia (K05) and cirrhosis of the liver (K70,74).

EBIC cost data was not sufficiently detailed for a number of these comorbidities, including type 2 diabetes (E11 – 14), pulmonary embolism (I26), aortic aneurysm (I71), venous thromboembolism (I80 – 82), intestinal ischemia (K55), gallbladder disease (K80 – 82) and chronic back pain (M45 – 54). In each of these situations, we estimated the costs based on the proportion of acute hospital days in 2011/12 for the disease of interest to the relevant comorbidity with EBIC 2008 costs. For example, hospital days for chronic back pain (M45 – 54) make up 21.6% and 19.6% (for men and women, respectively) of all hospital days for diseases of the musculoskeletal system and connective tissue (M00 – 99) in Canada in 2011/12. We therefore assumed that 21.6% and 19.6% of EBIC 2008 costs allocated to diseases of the musculoskeletal system and connective tissue (M00 – 99) for hospital care, physician care and drugs would be allocated to chronic back pain (M45 – 54).

These sex-specific direct care costs by comorbidity were then multiplied by the calculated risk factor–specific, sex-specific, and comorbidity-specific population-attributable fractions to calculate the direct care costs attributable to a given risk factor. We adjusted these direct costs in a multifactorial system to address double counting (previously describedReference 4).

Indirect costs

We calculated indirect costs (premature mortality, short- and long-term disability) following the method used in EBIC 1998 (a modified human-capital approach).Reference 13 Indirect costs attributable to premature mortality are based on the discounted present value of future production lost, including both the valuation of paid and unpaid work. Indirect costs attributable to short- and long-term disability are also based on lost production, taking into account both the severity and duration of the disability. Short-term disability is defined as a restriction of activity that is expected to last less than 6 months.

Specifically, the steps involved in estimating indirect costs were as follows:

  1. The diagnostic categories within EBIC 1998 that cover the comorbidities/diseases of interest were identified and the direct and indirect costs for these categories were extracted.
  2. The extracted costs were used to determine a ratio between direct and indirect costs for each of the diagnostic categories, stratified by the specific category of indirect cost (i.e. short-term disability, long-term disability and premature mortality).
  3. The pertinent ratios (by diagnostic category and specific indirect cost category) were applied to the previously identified direct costs attributable to each risk factor to generate the equivalent indirect cost data.
HA- and HSDA-level analysis of risk factor reduction

After calculating the adjusted economic burden attributable to the three risk factors in B.C. and each HA and HSDA, we determined which region in the province had the lowest overall prevalence rate for each risk factor. The sex- and age-specific prevalence rates from each of these three lowest-prevalence regions were applied to the population of each remaining region. This allowed us to calculate the difference in annual economic burden for each region using actual prevalence rates and hypothetical prevalence rates from those in the comparator regions.

Results

We estimated the economic burden attributable to excess weight, tobacco smoking and physical inactivity in B.C. in 2013 at $5.6 billion, with $2.6 billion (45.6%) attributable to excess weight, $2.0 billion to tobacco smoking (36.1%) and $1.0 billion (18.3%) to physical inactivity (see Table 1).

Table 1: Estimated prevalence of risk factors, total economic burden for multifactorial system, and disaggregated costs by risk factorTable 1 footnote a
  Population with RF,
%
# individuals with RF Direct cost per individual with RF,
$
Indirect cost per individual with RF,
$
Total cost per individual with RF,
$
Total direct cost of RF,
millions $
Total indirect cost of RF,
millions $
Total cost of RF,
millions $

Table 1 Footnotes

a     Adjusted for multiple RFs in one individual.

Abbreviation:

RF      risk factor

Males
Smokers Light 6.27 142 741 905 1655 2560 129.2 236.2 365.4
Moderate 3.90 88 701 1554 2830 4384 137.9 251.0 388.9
Heavy 3.91 89 029 2011 3635 5647 179.1 323.7 502.7
Subtotal - Male Smokers 14.07 320 471 1392 2530 3922 446.1 810.9 1257.0
Excess Weight Overweight 34.97 796 125 190 519 709 151.0 413.5 564.5
Obese 14.22 323 693 711 1592 2304 230.2 515.5 745.7
Subtotal - Male Excess Weight 49.18 1 119 818 340 830 1170 381.2 929.0 1310.2
Inactive 35.47 807 684 223 392 615 179.8 316.8 496.6
Subtotal - Males           1007.1 2056.7 3063.8
Females
Smokers Light 6.48 149 275 636 1115 1750 94.9 166.4 261.3
Moderate 3.66 84 354 1132 1990 3122 95.5 167.9 263.4
Heavy 2.11 48 607 1794 3146 4940 87.2 152.9 240.1
Subtotal - Female Smokers 12.24 282 236 984 1726 2710 277.6 487.2 764.8
Excess Weight Overweight 23.05 531 239 280 685 965 148.8 363.7 512.5
Obesity 11.00 253 560 954 1940 2893 241.8 491.8 733.6
Subtotal - Female Excess Weight 34.05 784 799 498 1090 1588 390.6 855.5 1246.1
Inactive 40.36 930 262 183 383 566 169.8 356.7 526.5
Subtotal - Females           838.0 1699.3 2537.4
Both Sexes
Smokers Light 6.37 292 016 767 1379 2146 224.1 402.7 626.7
Moderate 3.78 173 055 1349 2420 3769 233.4 418.9 652.2
Heavy 3.00 137 637 1935 3462 5397 266.3 476.6 742.8
Subtotal - Smokers 13.15 602 707 1201 2154 3355 723.7 1298.1 2021.8
Excess Weight Overweight 28.97 1 327 364 226 586 811 299.8 777.2 1077.0
Obesity 12.60 577 253 818 1745 2563 472.0 1007.3 1479.3
Subtotal - Excess Weight 41.57 1 904 617 405 937 1342 771.8 1784.5 2556.3
Inactive 37.93 1 737 946 201 388 589 349.6 673.5 1023.1
Total           1845.1 3756.1 5601.2
 

The annual risk factor-attributable economic burden per person is highest for all tobacco smokers ($3355), but ranges from $2146 for light smokers to $5397 for heavy smokers. The annual economic burden per person with excess weight is $1342 ($811 per overweight person and $2563 per obese person). While the annual economic burden per person with excess weight is substantially less than tobacco smoking, the high prevalence of excess weight (41.6%) compared to the prevalence of tobacco smoking (13.2%) in B.C. means that the total annual economic burden attributable to excess weight now exceeds that of tobacco smoking by 26%.

Among the HAs, the prevalence of smoking was higher than the provincial average in Interior Health, Northern Health and Vancouver Island Health, and the prevalence of excess weight was higher than the provincial average in all HAs except for Vancouver Coastal Health. Conversely, the prevalence of physical inactivity was lower than the provincial average in Interior Health and Vancouver Island Health. The prevalence of all three risk factors was above the provincial average in Northern Health (see Table 2). The total economic burden attributable to these three risk factors across HAs ranged from $453.0 million in Northern Health to $1997.1 million in Fraser Health.

Table 2. Estimated prevalence of risk factors, total economic burden for multifactorial system, and disaggregated costs by risk factor, British Columbia Health Authorities, 2013, by sex adjusted for multiple risk factors in one individual
  Population with RF,
%
Number of individuals with RF,
n
Direct cost per individual with RF,
$
Indirect cost per individual with RF,
$
Total cost per individual with RF,
$
Total direct cost of RF,
millions $
Total indirect cost of RF,
millions $
Total cost of RF,
millions $

Abbreviation:

RF      risk factor

Interior Health
Smokers Light 7.78 55 791 682 1228 1910 38.0 68.5 106.5
Moderate 6.57 47 159 1114 2001 3115 52.5 94.4 146.9
Heavy 4.02 28 809 1693 3028 4721 48.8 87.2 136.0
Subtotal - Smokers 18.36 131 759 1058 1898 2956 139.3 250.1 389.4
Excess Weight Overweight 31.42 225 430 227 586 813 51.1 132.2 183.3
Obesity 15.12 108 516 793 1701 2494 86.1 184.6 270.7
Subtotal - Excess Weight 46.55 333 946 411 949 1359 137.2 316.7 454.0
Inactive 33.02 236 878 211 406 616 49.9 96.1 146.0
Total           326.4 663.0 989.4
Fraser Health
Smokers Light 5.72 96 722 807 1448 2255 78.1 140.1 218.1
Moderate 2.84 47 920 1431 2560 3990 68.6 122.7 191.2
Heavy 2.78 47 053 1999 3586 5586 94.1 168.7 262.8
Subtotal - Smokers 11.34 191 696 1256 2251 3506 240.7 431.5 672.1
Excess Weight Overweight 30.12 509 054 216 561 777 110.2 285.4 395.6
Obesity 12.83 216 835 782 1670 2452 169.5 362.1 531.6
Subtotal - Excess Weight 42.96 725 889 385 892 1277 279.7 647.5 927.2
Inactive 41.62 703 405 193 372 565 135.9 261.9 397.7
Total           656.3 1340.8 1997.1
Vancouver Coastal Health
Smokers Light 6.10 69 486 782 1402 2184 54.3 97.4 151.8
Moderate 2.46 28 029 1545 2779 4324 43.3 77.9 121.2
Heavy 1.49 16 920 2387 4255 6642 40.4 72.0 112.4
Subtotal - Smokers 10.05 114 436 1206 2161 3368 138.0 247.3 385.4
Excess Weight Overweight 24.65 280 721 223 583 806 62.5 163.8 226.3
Obesity 7.13 81 208 900 1892 2792 73.1 153.6 226.7
Subtotal - Excess Weight 31.79 361 929 375 877 1252 135.7 317.4 453.1
Inactive 38.35 436 704 188 362 550 82.0 158.2 240.2
Total           355.7 723.0 1078.7
Island Health
Smokers Light 6.67 50 179 827 1489 2316 41.5 74.7 116.2
Moderate 4.57 34 377 1363 2444 3807 46.9 84.0 130.9
Heavy 3.35 25 196 1981 3536 5517 49.9 89.1 139.0
Subtotal - Smokers 14.59 109 752 1260 2258 3518 138.3 247.9 386.1
Excess Weight Overweight 28.86 217 084 251 649 901 54.5 141.0 195.5
Obesity 14.99 112 728 862 1849 2711 97.2 208.4 305.6
Subtotal - Excess Weight 43.85 329 812 460 1059 1519 151.7 349.4 501.1
Inactive 32.64 245 496 227 437 664 55.8 107.3 163.0
Total           345.8 704.5 1050.2
Northern Health
Smokers Light 7.10 20 154 749 1352 2101 15.1 27.3 42.4
Moderate 5.95 16 902 1172 2101 3273 19.8 35.5 55.3
Heavy 7.17 20 357 1406 2518 3924 28.6 51.3 79.9
Subtotal - Smokers 20.23 57 413 1106 1986 3092 63.5 114.0 177.5
Excess Weight Overweight 31.61 89 713 234 602 836 21.0 54.0 75.0
Obesity 18.72 53 135 781 1683 2464 41.5 89.4 130.9
Subtotal - Excess Weight 50.33 142 847 437 1004 1441 62.5 143.4 205.9
Inactive 38.66 109 736 217 416 634 23.8 45.7 69.5
Total           149.8 303.2 453.0
 

The prevalence of excess weight varies by HSDA, from a low of 29.5% in the Vancouver HSDA to a high of 56.7% in the Northwest HSDA (B.C. average = 41.6%; see Figure 1). The prevalence of physical inactivity varies from a low of 27.1% in the Kootenay Boundary HSDA to a high of 43.8% in the Fraser North HSDA (B.C. average = 37.9%; see Figure 2). The prevalence of tobacco smoking varies from a low of 8.8% in the Richmond HSDA to a high of 21.3% in the Northeast HSDA (B.C. average = 13.2%; see Figure 3).

Figure 1. Prevalence of excess weight in British Columbia, by excess weight Category and HSDA, 2011/12

Figure 1

Abbreviations:

BMI           body mass index

HSDA       health service delivery area

Text Equivalent - Figure 1

Figure 1 shows that the prevalence of excess weight varies by HSDA, from a low of 29.5% in the Vancouver HSDA to a high of 56.7% in the Northwest HSDA (B.C. average = 41.6%).

Enlarge Figure 1

 

Figure 2. Prevalence of physical inactivity in British Columbia, by HSDA, 2011/12

Figure 2

Abbreviation:

HSDA       health service delivery area

Text Equivalent - Figure 2

Figure 2 shows that the prevalence of physical inactivity varies from a low of 27.1% in the Kootenay Boundary HSDA to a high of 43.8% in the Fraser North HSDA (B.C. average = 37.9%).

Enlarge Figure 2

 

Figure 3. Prevalence of smoking in British Columbia, by smoking intensity and HSDA, 2011/12

Figure 3

Abbreviation:

HSDA       health service delivery area

Text Equivalent - Figure 3

Figure 3 shows that the prevalence of tobacco smoking varies from a low of 8.8% in the Richmond HSDA to a high of 21.3% in the Northeast HSDA (B.C. average = 13.2%).

Enlarge Figure 3

 

The variable prevalence rates of the three risk factors in each HSDA results in a varying economic burden per capita in each region (see Figure 4). The Richmond HSDA has the lowest per capita economic burden at $738, while the Northwest HSDA has the highest at $1766, more than double that of the Richmond HSDA. The provincial average per capita economic burden is $1222.

Figure 4. Economic burden per capita in British Columbia: smoking, excess weight and physical inactivity, by HSDA, 2013

Figure 4

Abbreviation:

HSDA       health service delivery area

Text Equivalent - Figure 4

Figure 4 shows that the variable prevalence rates of the three risk factors in each HSDA results in a varying economic burden per capita in each region. The Richmond HSDA has the lowest per capita economic burden at $738, while the Northwest HSDA has the highest at $1766, more than double that of the Richmond HSDA. The provincial average per capita economic burden is $1222.

Enlarge Figure 4

 

Applying the lowest sex- and age-specific prevalence rates for excess weight from the Vancouver HSDA, for tobacco smoking from the Richmond HSDA and for physical inactivity from the Kootenay Boundary HSDA to the population of each remaining HSDAs in the province would reduce the per capita annual economic burden by between $60 (in the Richmond HSDA) and $651 (in the Northwest HSDA) (see Figure 5).

Figure 5. Changes in annual per capita economic burden in British Columbia based on best risk factor rates, by HSDA and direct/indirect costs ($Millions), 2013

Figure 5

Note: Sensitivity analysis suggests that these costs may vary by +/−17%.

Abbreviations:

B.-C.         British Columbia

HSDA       health service delivery area

Text Equivalent - Figure 5
Figure 5 shows that applying the lowest sex- and age-specific prevalence rates for excess weight from the Vancouver HSDA, for tobacco smoking from the Richmond HSDA and for physical inactivity from the Kootenay Boundary HSDA to the population of each remaining HSDAs in the province would reduce the per capita annual economic burden by between $60 (in the Richmond HSDA) and $651 (in the Northwest HSDA).
Changes in Annual Per Capita Economic Burden ($Millions) Health service delivery area (HSDA)
BC E. Kootenay Kootenay
Boundary
Okanagan Thompson Fraser E. Fraser N. Fraser S. Vancouver Richmond N. Shore S. Van.
Island
Central Van.
Island
N. Van.
Island
Northwest N. Interior Northeast

Note: Sensitivity analysis suggests that these costs may vary by +/−17%.

Abbreviations:

B.-C.       British Columbia

HSDA      health service delivery area

Indirect −$199 −$357 −$238 −$251 −$264 −$309 −$179 −$178 −$67 −$40 −$64 −$168 −$290 −$274 −$439 −$423 −$315
Direct −$98 −$177 −$122 −$126 −$132 −$154 −$88 −$84 −$35 −$20 −$30 −$80 −$145 −$141 −$211 −$214 −$157
 

Enlarge Figure 5

 

The total annual reduction in economic burden would range between $12.1 million in the Richmond HSDA to $200.1 million in the Fraser South HSDA (see Figure 6). If all HSDAs were to achieve the best prevalence rates for the three risk factors, then $1362.2 million in economic burden could be avoided annually, comprising $449.8 million in direct costs and $912.4 million in indirect costs.

Figure 6. Changes in annual economic burden in British Columbia based on best risk factor rates, by HSDA and direct/indirect costs ($Millions), 2013

Figure 6

Note: Sensitivity analysis suggests that these costs may vary by +/−17%.

Abbreviation:

HSDA       health service delivery area

Text Equivalent - Figure 6
Figure 6 shows that the total annual reduction in economic burden would range between $12.1 million in the Richmond HSDA to $200.1 million in the Fraser South HSDA. If all HSDAs were to achieve the best prevalence rates for the three risk factors, then $1362.2 million in economic burden could be avoided annually, comprising $449.8 million in direct costs and $912.4 million in indirect costs.
Health service delivery area (HSDA) Changes in Annual Economic Burden ($Millions)
E. Kootenay Kootenay
Boundary
Okanagan Thompson Fraser E. Fraser N. Fraser S. Vancouver Richmond N. Shore S. Van.
Island
Central Van.
Island
N. Van.
Island
Northwest N. Interior Northeast

Note: Sensitivity analysis suggests that these costs may vary by +/−17%.

Abbreviation:

HSDA      health service delivery area

Indirect −$27.1 −$18.3 −$87.1 −$57.4 −$88.8 −$114.1 −$136.6 −$44.3 −$8.1 −$17.8 −$62.5 −$76.0 −$32.6 −$31.9 −$60.0 −$21.9
Direct −$13.5 −$9.3 −$43.5 −$28.8 −$44.2 −$55.9 −$64.6 −$23.0 −$4.0 −$8.4 −$29.6 −$38.0 −$16.8 −$15.4 −$30.3 −$10.9
 

Discussion

We estimated the annual economic burden attributable to excess weight, tobacco smoking and physical inactivity in B.C. at $5.6 billion in 2013, with a higher proportion of this total attributable to excess weight ($2.6 billion) than to tobacco smoking ($2.0 billion). While B.C. has lower prevalence rates of the risk factors than any other Canadian province,Reference 1 rates vary significantly within the province. If each HSDA in the province were to achieve the best prevalence rates for the three risk factors, then $1.36 billion in economic burden could be avoided annually. This suggests that a 24% reduction in the economic burden attributable to excess weight, tobacco smoking and physical inactivity in B.C. is possible if all regions achieved rates of these risk factors that are best in the province. It is important to note, however, that a reduction in economic burden is not equivalent to cost savings. Even for direct costs, the majority of resources freed up over time will likely be re-allocated (intentionally or unintentionally) elsewhere within health care.

A similar analysis using age- and sex-specific prevalence rates from B.C. applied to populations living in the other Canadian provinces indicated that the annual economic burden in Canada attributable to these three risk factors would be reduced by $5.3 billion, or 10.0% of the $52.8 billion total economic burden of the risk factors.Reference 1 The intraprovincial variation in the prevalence of the risk factors thus seems to be substantially higher than the variation between provinces.

This study identified notable disparities in the prevalence of each risk factor across health regions, which were mirrored in each region's attributable economic burden. Rates of excess weight were much lower in Vancouver Coastal Health than all other health authorities. Physical inactivity levels were typically much higher in regions with a higher population density (particularly in the Fraser North, Fraser East, Vancouver and Richmond HSDAs) compared to more rural populations. Conversely, smoking rates were much lower in urban areas than rural areas. Risk factor rates were almost always above the provincial average in the north of the province (Northwest, Northern Interior and Northeast HSDAs).

The obesity epidemic has been labelled by some as the "new tobacco" based on both its rapidly increasing prevalence worldwide and the tide of associated health consequences. Rates of tobacco smoking have decreased dramatically in recent decades, and this progress should reinforce that similar successes are also possible for other modifiable risk factors.Reference 14,Reference 15 We have learned from our experiences with smoking that a comprehensive, multipronged approach is required to achieve substantial reductions.Reference 16 The reduction in smoking rates could not be solely attributed to one or two interventions; rather it was the culmination of economic and policy interventions, community-based interventions and clinical interventions that acted synergistically to lower smoking rates to where they are now. We have also learned that to see a meaningful reduction in the prevalence of risk factors, a long-term approach is required. The problem of tobacco smoking was not solved by a quick fix, and it is unlikely that other modifiable risk factors will be either. Instead, interventions require multigenerational approaches that span beyond the immediate political cycle.

For the purpose of this study, we focussed on the costs associated with individual-level risk factors, but also acknowledged that excess weight, physical inactivity and tobacco smoking are strongly influenced by a variety of social, environmental and economic factors. These determinants are likely to drive some of the geographical variation that we observed in this study, and these underlying factors should also be considered in an effort to promote health equity. Not everyone has an equal opportunity to make healthy choices, and any population-level interventions should address chronic disease risk factors while acknowledging the social determinants of health.

The inclusion of indirect costs in any economic analysis is controversial given that a variety of approaches exist, all of which generate very different results.Reference 17,Reference 18,Reference 19,Reference 20 In 1998, EBIC used a modified human-capital approachFootnote , changing to the friction cost methodFootnote in 2008. The resulting indirect costs vary substantially (see Table 3).

Table 3: Economic burden of illness in Canada by diagnostic category, indirect costs as a percentage of direct costs
Diagnostic Category EBIC 1998
(Human capital)
EBIC 2008
(Friction)
Mortality,
%
Morbidity,
%
Total,
%
Mortality,
%
Morbidity,
%
Total,
%

Abbreviation:

EBIC      economic burden of illness in Canada

Malignant and other neoplasms 431 46 478 3.5 8.8 12.3
Endocrine, nutritional and metabolic diseases 64 55 119 0.4 2.5 2.9
Cardiovascular diseases 121 50 171 0.8 2.3 3.1
Respiratory diseases / Infections 48 99 146 0.3 46.8 47.1
Digestive diseases 32 33 65 0.4 2.7 3.2
Musculoskeletal diseases 5 514 519 0.0 24.1 24.2
 

If the friction cost method were applied to the current model, the indirect economic burden attributable to the three risk factors in B.C. would be reduced from $3756 million to $238 million. The focus of the friction cost method is on lost production from the "perspective of firms, consumers and society, without accounting for the potential income lost on an individual basis,"Reference 2,p.452 nor does it value potential time lost due to morbidity or mortality. That is, while smoking may reduce a person's life by an average of 11 to 12 years,Reference 22 the friction cost method only applies a value on the time period that it takes to replace this person in the workforce. Placing an economic value on time lost due to disability and premature mortality (as in the modified human-capital approach) allows us to compare the broader effect of the risk factors on society as a whole, rather than from a narrow focus on production losses.

Strengths and limitations

Despite all efforts to optimize the accuracy of the analysis, some limitations remain. Most studies, including this one, categorize people with a BMI between 25 kg/m2 and 29.9 kg/m2 as overweight. This range, especially the lower end, has been historically dynamic, however.Reference 16 Recent research has suggested that a more appropriate lower boundary with respect to negative health effects might be 27 kg/m2,Reference 23 or even below 25 kg/m2 for certain people, particularly those of Asian descent.Reference 24 This is relevant to the current study as a high proportion of people in B.C. identify as a visible ethnic minority (24.8%),Reference 25 with some regions much higher than others. For example, in the Richmond HSDA, 44% of people identify as being of Chinese origin, 8.0% as South Asian, and 5.5% as Filipino. Using a cut-off of 25 kg/m2 for this population may underestimate their excess weight-attributable economic burden.

The method of scaling up from direct to indirect costs depends on the assumption that the ratios of costs have not changed over time. In addition, the source for the relative risks associated with smokingReference 7 and physical inactivityReference 9 adjust for known confounding factors in generating disease-specific relative risks. The meta-analyses for the relative risks associated with overweight and obesity, however, did not include physical inactivity as a potentially confounding risk factor,Reference 8 which may lead to an overestimate of the economic burden attributable to excess weight. On the other hand, relative risks calculated in this meta-analysis are based on a combination of studies including both self-reported and objective measures of BMI while our model uses the prevalence of excess weight based on self-reported height and weight, which may lead to an underestimate of the economic burden attributable to excess weight. Previous sensitivity analysis also suggests that the true economic burden may vary by +/−17% of our best estimate.Reference 2 Finally, the allocation of non-hospital costs to HAs and HSDAs in proportion to the allocation of hospital-related costs may over- or underestimate these costs in a given region of the province.

Conclusion

Our findings suggest that the economic burden of excess weight, physical inactivity and tobacco smoking are substantial and vary considerably between health regions in B.C. However, by reducing the prevalence of each of the three risk factors across the province to that of the region with the lowest prevalence, the associated direct and indirect costs could be reduced by about one quarter. Knowing this, prioritizing prevention initiatives should be at the forefront of system- and community-level changes. The economic evidence we present also suggests that various regions within B.C. demand specific attention. In particular, the geographical variations between health authorities and HSDAs may act as a guideline for where region-specific prevention efforts may be most valuable. A variety of social, environmental and economic factors likely drive some of this geographical variation and these underlying factors should be considered when developing prevention programs in an effort to promote health equity.

Acknowledgements

This study was carried out as a part of a joint work plan in population health surveillance programs between the Ministry of Health and Provincial Health Services Authority (PHSA). The authors thank Lydia Drasic (Executive Director, BCCDC Operations and Chronic Disease Prevention, PHSA) and Silas Brownsey (Executive Director, Population and Public Health, BC Ministry of Health) for sponsoring the study project.

References

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