Dose–response relationship between functional pain interference and nonmedical analgesic use: Findings from a nationally representative Canadian survey

Figures & data

Table 1. Weighted estimates of functional pain interference from Canadian Community Health Survey–Mental Health (2012).^a

Variable	Total ’000 (%)	No pain ’000 (%)	Pain prevents no activities ’000 (%)	Pain prevents few activities ’000 (%)	Pain prevents some activities ’000 (%)	Pain prevents most activities ’000 (%)
Functional pain interference	28 051 (100.0)	22 261 (79.4)	1733 (6.2)	1725 (6.1)	1314 (4.7)	1018 (3.6)
Nonmedical analgesic use
No	26 193 (93.4)	21 085 (75.2)	1594 (5.7)	1547 (5.5)	1116 (4.0)	850 (3.0)
Yes	1858 (6.6)	1176 (4.2)	139 (0.5)	177 (0.6)	198 (0.7)	168 (0.6)
Age
15–19 years	2284 (8.1)	20 995 (7.5)	56 (0.2)	79 (0.3)	30 (0.1)	19 (0.1)
20–29 years	4414 (15.7)	38 636 (13.8)	184 (0.7)	180 (0.6)	113 (0.4)	74 (0.3)
30–39 years	4418 (15.7)	38 131 (13.6)	208 (0.7)	180 (0.6)	124 (0.4)	94 (0.3)
40–49 years	4901 (17.5)	38 891 (13.9)	282 (1.0)	332 (1.2)	204 (0.7)	194 (0.7)
50–59 years	5208 (18.6)	38 823 (13.8)	400 (1.4)	333 (1.2)	349 (1.2)	243 (0.9)
60–69 years	3682 (13.1)	26 230 (9.4)	301 (1.1)	314 (1.1)	241 (0.9)	203 (0.7)
70–79 years	2109 (7.5)	13 994 (5.0)	201 (0.7)	210 (0.7)	180 (0.6)	119 (0.4)
≥80 years	1035 (3.7)	6907 (2.5)	101 (0.4)	97 (0.3)	73 (0.3)	73 (0.3)
Sex
Male	13 800 (49.2)	11 303 (40.3)	833 (3.0)	708 (2.5)	525 (1.9)	431 (1.5)
Female	14 251 (50.8)	10 958 (39.1)	900 (3.2)	1017 (3.6)	789 (2.8)	587 (2.1)
Highest education completed
<Secondary school graduation	5066 (18.1)	3715 (13.2)	368 (1.3)	382 (1.4)	305 (1.1)	296 (1.1)
≥Secondary school graduation	22 985 (81.9)	18 545 (66.1)	1366 (4.9)	1343 (4.8)	1009 (3.6)	722 (2.6)
Culture/race
White	21 598 (77.0)	16 931 (60.4)	1390 (5.0)	1408 (5.0)	1053 (3.8)	816 (2.9)
Non-white	6453 (23.0)	5329 (19.0)	343 (1.2)	317 (1.1)	261 (0.9)	202 (0.7)
Chronic mental illness^b
No	24 621 (87.8)	20 229 (72.1)	1514 (5.4)	1323 (4.7)	936 (3.3)	619 (2.2)
Yes	3430 (12.2)	2032 (7.2)	220 (0.8)	402 (1.4)	378 (1.3)	399 (1.4)

^aAll frequencies and percentages are probability weighted using Statistics Canada sampling weights. Frequencies displayed in this table have been rounded to the nearest thousand. Percentages may not total to 100% due to rounding.

^bDefined as “yes” to any of chronic fatigue, mood disorder including depression, anxiety disorder, posttraumatic stress disorder, or attention deficit disorder, versus “no” to all

Figure 1. Study sample derived from the Canadian Community Health Survey–Mental Health.

Table 2. Bivariable and multivariable weighted^a logistic regression examining the relationship between functional pain interference and NMAU.

Variable	NMAU OR
	Unadjusted OR (95% CI)	Adjusted OR^b (95% CI)
Functional pain interference
No pain	Reference	Reference
Pain prevents no activities	1.57 (1.19–2.05)	1.61 (1.22–2.12)
Pain prevents a few activities	2.06 (1.59–2.66)	1.94 (1.49–2.53)
Pain prevents some activities	3.18 (2.43–4.18)	2.91 (2.20–3.85)
Pain prevents most activities	3.54 (2.67–4.70)	2.98 (2.21–4.01)
Age
15–19 years	1.78 (1.17–2.70)	2.11 (1.38–3.24)
20–29 years	2.19 (1.51–3.17)	2.47 (1.67–3.66)
30–39 years	1.38 (0.96–1.97)	1.56 (1.06–2.28)
40–49 years	1.62 (1.11–2.37)	1.67 (1.13–2.47)
50–59 years	1.90 (1.27–2.84)	1.82 (1.20–2.74)
60–69 years	1.56 (1.05–2.34)	1.50 (0.99–2.27)
70–79 years	1.25 (0.84–1.85)	1.18 (0.79–1.77)
≥80 years	Reference	Reference
Sex
Male	1.20 (1.01–1.44)	1.32 (1.10–1.58)
Female	Reference	Reference
Highest education completed
<Secondary school graduation	1.09 (0.89–1.34)	1.03 (0.83–1.28)
≥Secondary school graduation	Reference	Reference
Culture/race
White	Reference	Reference
Non-white	0.79 (0.63–0.99)	0.83 (0.66–1.04)
Chronic mental illness^c
No	Reference	Reference
Yes	3.09 (2.57–3.72)	2.39 (1.98–2.87)

^aAll estimates are probability weighted using Statistics Canada sampling weights.

^bAdjusted for age, sex, highest education completed, culture/race, and chronic mental illness.

^cDefined as “yes” to any of chronic fatigue, mood disorder including depression, anxiety disorder, post traumatic stress disorder, or attention deficit disorder, versus “no” to all.

NMAU = nonmedical analgesic use; OR = odds ratio; CI = confidence interval.

Figure 2. Adjusted odds ratios and 95% confidence intervals for nonmedical analgesic use stratified by functional pain interference, controlling for age, sex, highest education completed, culture/race, and chronic mental illness.

Figure 3. Adjusted odds ratios and 95% confidence intervals for nonmedical analgesic use stratified by age, controlling for functional pain interference, sex, highest education completed, culture/race, and chronic mental illness.

Table 3. Weighted^a multivariable logistic regression analyses examining the odds of functional pain interference on nonmedical analgesic use, within strata of chronic mental illness and age groupings.

Variable	Pain prevents no activities^b AOR (95% CI)	Pain prevents few activities^b AOR (95% CI)	Pain prevents some activities^b AOR (95% CI)	Pain prevents most activities^b AOR (95% CI)
Chronic mental illness^c
No	1.41 (1.02–1.96)	2.06 (1.49–2.85)	2.67 (1.88–3.81)	2.75 (1.81–4.17)
Yes	2.30 (1.37–3.88)	1.70 (1.10–2.65)	3.43 (2.19–5.35)	3.37 (2.17–5.23)
Age^d
15–19 years	2.16 (0.66–7.02)	1.18 (0.49–2.83)	0.46 (0.13–1.70)	4.28 (1.00–18.21)
20–29 years	2.97 (1.65–5.35)	2.69 (1.34–5.38)	4.38 (2.00–9.60)	1.03 (0.42–2.56)
30–39 years	2.00 (1.05–3.79)	1.19 (0.59–2.40)	4.80 (2.38–9.67)	3.12 (1.44–6.77)
40–49 years	1.88 (0.94–3.76)	2.11 (1.08–4.10)	3.16 (1.65–6.06)	3.29 (1.57–6.86)
50–59 years	1.01 (0.50–2.03)	1.77 (1.03–3.06)	2.15 (1.23–3.74)	2.80 (1.65–4.75)
60–69 years	0.67 (0.32–1.38)	1.19 (0.61–2.32)	3.14 (1.64–6.04)	4.07 (2.02–8.21)
70–79 years	1.34 (0.60–3.01)	3.24 (1.65–6.37)	1.75 (0.74–4.16)	2.77 (1.19–6.46)
≥80 years	3.68 (1.42–9.55)	2.57 (1.07–6.22)	3.37 (1.38–8.24)	3.66 (1.42–9.45)

^aAll estimates are probability weighted using Statistics Canada sampling weights.

^bCompared to reference category of “no pain.”

^cAdjusted for sex, highest education completed, culture/race, and age.

^dAdjusted for sex, highest education completed, culture/race, and chronic mental illness.

AOR = adjusted odds ratio; CI = confidence interval.