Non-medical use of prescription opioids among Ontario adults: data from the 2008/2009 CAMH Monitor.

Shield, Kevin D. ; Ialomiteanu, Anca ; Fischer, Benedikt 等

Prescription opioid analgesics (PO) use in North America has become a major medical and public health concern with consumption of PO in Canada and the United States (US) being higher than anywhere else in the world. (1-3) In Canada, the amount of PO dispensed has doubled in the last decade alone. (1) Additionally, the number of opioid-related deaths (both prescription and illegal opioids) in Canada increased 41% from 1999 to 2004. (4) An analogous situation exists in the US, where the prevalence of PO use and non-medical prescription opioid analgesics use (NMPOU) and the incidence of mortality and morbidity associated with NMPOU have increased since the early 1990s. (5-7)

Prevalence of PO use and the amount of PO dispensed in a population for medical purposes is associated with 1) the prevalence of NMPOU, (2,8,9) and 2) the mortality and morbidity associated with opioid use (e.g., deaths due to overdose, and admissions to emergency rooms and treatment facilities for substance abuse), albeit with a time lag. (4,10) While the associations with PO use can be used to indirectly estimate NMPOU prevalence, (9) another possibility is to use surveys such as the Canadian Alcohol and Drug Use Monitoring Survey (CADUMS) 2008 which may be used to directly estimate the prevalence of NMPOU. (11)

However, NMPOU prevalence for Canada as measured by the CADUMS 2008 seems unrealistically low when compared to data obtained from the US National Survey on Drug Use and Health (NSDUH) (12,13) given per capita use in both countries. (1) Various reasons have been suggested for the differences between the results obtained from the CADUMS 2008 and the NSDUH, such as sampling methods, response rates and item formulation. (13-16)

Utilizing the CAMH Monitor 2008 and 2009 to estimate the types of PO use in Ontario has many advantages over using the CADUMS 2008. Most importantly, the CAMH Monitor had a region-stratified sampling design as well as a higher response rate and, thus, should give more accurate results. (16-18) In this article, we use data from the CAMH Monitor 2008 and 2009 to assess: 1) the prevalence of a) PO use, b) PO use for intoxication purposes, and c) NMPOU; and 2) the associations of demographic variables with the types of PO use.

METHODS

Survey design

Our study is based on data derived from the 2008 and 2009 cycles of the CAMH Monitor, a county-stratified two-stage (telephone household, respondent) probability sampling of Ontario adults (18 years and older) performed in 24 waves between January 2008 and December 2009. The survey was conducted using random-digit-dialing methods and computer-assisted telephone interviewing with a response rate of 57% (see refs. 17 and 18 for sampling design details). Our analysis is based on a total sample of 2,030 adults. A posteriori population expansion weights were calculated for the CAMH Monitor by triangulating survey data with census information on age and gender.

Selection of variables for analysis

The main PO indicators of interest from the CAMH Monitor 2008 and 2009 were as follows: 1) use of PO in the "past 12 months" (i.e., medical or non-medical); 2) any NMPOU in the previous 12 months as computed by combining the responses of participants who reported they had used PO during the previous 12 months "to get high" and had a) used PO obtained "from a prescription written for someone else", or b) used PO "bought from someone else, without a prescription" or "from any other source"; and 3) any use of PO for intoxication purposes was assessed by using PO during the "past 12 months" on at least one occasion "to get high?" (see refs. 17 and 18 for wording details).

Demographic variables included in our analysis included gender, age (grouped into three categories: 18-29, 30-54, 55+), region (living in Toronto, the rest of Ontario) and household income (<$30,000, $30,000-79,000, $80,000+, not stated).

Substance use measures included tobacco use (defined as either daily or occasional (in the last 12 months) cigarette smoking), weekly binge drinking (defined as drinking five or more drinks on one occasion at least once a week in the previous 12 months), and cannabis use (defined as using cannabis at least once in the previous 12 months).

Psychological distress was measured by the 12-item General Health Questionnaire (GHQ-12), (19) a screening instrument that evaluates depression/anxiety and problems with social functioning. We used a cut-off score of 3 or more on the GHQ-12 as an indication of elevated psychological distress.

Statistical analyses

The results in this paper are based on "valid" responses (n's), such that missing data (i.e., "don't know" responses and refusals to respond) were excluded from our analyses. Stata 10.1 and SPSS 15.0 software were employed for our analyses. (20,21)

Prevalence of 1) any use of POs, 2) any NMPOU, and 3) the use of POs for intoxication purposes, was assessed for all of Ontario and by age, region, income, binge drinking, tobacco use, cannabis use and psychological distress. Any estimate with a coefficient of variation above 33.3 was considered unstable and should be interpreted with caution. Confidence intervals for the prevalence of PO use, NMPOU, and the use of POs for intoxication purposes were calculated using the normal approximation as this method is deemed the most appropriate for complex survey data. (22) Significant differences were determined using chi-square tests. A posteriori population weights were used to estimate the prevalence of the types of PO use and in all bivariate analyses.

Two-step logistic regression models were implemented, one for men and one for women, to determine the variables associated with NMPOU. In step 1, we assessed the impact of demographic factors (age, region, and income); in step 2, we examined the impact of substance use (tobacco, cannabis, binge drinking) and psychological distress on NMPOU while also controlling for demographic factors. In all logistic regression models, variance inflation factors (VIF) were examined, with a VIF >5 considered evidence of collinearity. Model fit was assessed using the Hosmer-Lemeshow Goodness of Fit Test. (23) A modelling approach suggested by Groves was adopted so that we did not take into account a posteriori population expansion weights in our regression analyses. (24)

RESULTS

Table 1 presents data on the use of PO by demographic characteristics, substance use and psychological distress. Any use of POs was reported by 21.3% (95% CI 19.1-23.4) of Ontario adults. No significant differences were found between men (19.9%, 95% CI 16.9-22.9) and women (22.7%, 95% CI 19.6-25.9). Bivariate analyses revealed significant differences only for psychological distress. Use of any PO was significantly higher among those reporting elevated psychological distress (37.3%, 95% CI 30.0-44.6). No significant differences were found for age, region, income, tobacco use, binge drinking and cannabis use.

Any NMPOU was reported by 2.0% (95% CI 1.2-2.8) of Ontario adults. There were no significant differences between men (2.4%, 95% CI 1.0-3.7) and women (1.6%, 95% CI 0.8-2.5). Significant differences were found only for cannabis use and psychological distress. Any NMPOU was significantly higher among those reporting cannabis use in the previous 12 months (6.3%, 95% CI 2.0-10.7 versus 1.0%, 95% CI 0.2-1.8) and among those reporting elevated psychological distress (7.5%, 95% CI 3.1-11.9 versus 1.2%, 95% CI 0.6-1.7).

Any use of POs for intoxication purposes was reported by 0.5% (95% CI 0.0-1.0) of Ontario adults. No significant differences were found between men (0.8%, 95% CI 0.0-1.7) and women (0.2%, 95% CI 0.0-0.5). Significant differences were found for age, tobacco use, cannabis use and psychological distress. Use of any POs for intoxication purposes was reported more frequently among those aged 18 to 29 (1.8%, 95% CI 0.0-4.4), among current smokers (1.7%, 95% CI 0.0-4.1), among people who used cannabis during the previous 12 months (2.7%, 95% CI 0.0-6.2), and among those reporting elevated psychological distress (2.4%, 95% CI 0.0-5.8).

In Table 2, we restrict our analysis to NMPOU only and present data separately for men and women by demographic characteristics, substance use and psychological distress. For both men and women, we found no significant differences by age, region, income and weekly binge drinking. Among women, NMPOU was significantly associated only with tobacco use but not weekly binge drinking, cannabis use or psychological distress. Among men, NMPOU was significantly associated with tobacco use, cannabis use and psychological distress. Use was significantly higher among tobacco smokers (6.5%, 95% CI 1.6-11.3 versus 1.2%, 95% CI 0.3-2.1), among cannabis users (8.6%, 95% CI 2.3-14.4 versus 1.0%, 95% CI 0.2-1.8) and among men reporting elevated psychological distress (14.0%, 95% CI 4.1-23.9 versus 1.0%, 95% CI 0.3-1.7).

Table 3 presents logistic regression models of NMPOU for men and women, controlling for demographic characteristics in step 1 and for added substance use and psychological distress in step 2. Demographic characteristics (age, income and region) were not found to be significant predictors of NMPOU for women in step 1; however, age was found to be a significant predictor of NMPOU in men. When these factors were controlled for and substance use and psychological distress were included in step 2, cannabis use (OR=4.64) and psychological distress (OR=7.55) became significant predictors of NMPOU for men. For women, the logistic regression in step 2 revealed that psychological distress (OR=4.21) was significantly associated with NMPOU.

DISCUSSION

This study explored the prevalence and covariates of NMPOU in the Ontario adult general population. The key results from our analysis demonstrate, first of all, that NMPOU is not significantly associated with sex, age, income or region. As was the case in other studies, we found evidence to suggest that the predictors of NMPOU in Ontario are different for men and women in terms of age, cigarette smoking and psychological distress. (25-28) In addition to differences in the significance of these predictors, we also found a difference in the significance of cannabis use in the previous year as a predictor of NMPOU for men and women. Despite differences in the significance of predictors, the prevalence of NMPOU in Ontario was not significantly different by sex, as has been observed in countries other than Canada. (28-30) Although more research is needed to confirm these observations, it appears that all types of PO use, with the exception of PO use by younger adults for intoxication purposes, are equally prevalent in adult men and women of all income levels and regions in Ontario. PO use, either medically or non-medically, is the only psychoactive substance with no demographic differentiation; alcohol, tobacco and almost all illegal drugs are more prevalent in men and younger age groups, and benzodiazepine and most psychoactive medications are more prevalent in women and the elderly. In other words, NMPOU seems to be the first substance abuse problem that penetrates both sexes and different social strata almost at the same level.

Bivariate analysis indicated that PO use, NMPOU, and use of POs for intoxication purposes were all associated with psychological distress, and that NMPOU and PO use for intoxication purposes were significantly associated with cannabis use. Additionally, our logistic regression of NMPOU found that psychological distress and cannabis use were associated with the odds of NMPOU in the previous 12 months for men but not for women. The results from our study confirm previous results that suggest the NMPOU is associated with illicit drug use and mental illness in men. (28-30) This result confirms findings from a number of other recent studies, which have shown pronounced correlations between NMPOU and mental health problems as well as other substance use problems. (31-33) Thus, NMPOU commonly does not occur in isolation but occurs in the context of concomitant substance use and/or mental health disorders, the interaction dynamics of which are not well understood but have crucial implications for interventions.

This study is limited by the sample size available for analysis from the CAMH Monitor 2008 and 2009. Despite using two waves of a fairly large survey that provided a sample of 858 men and 1,070 women, we were not able to acquire a significant result for odds ratios below 3.0. Additionally, because of the small sample size, estimates of NMPOU when stratified by predictors were unstable (defined as having a coefficient of variation equal to or greater than 33.3). Unstable estimates were also a problem when stratifying by various variables the use of POs for intoxication purposes. Our finding that NMPOU in Ontario was 2.0% (2.4% of men and 1.6% of women) suggests that either a study investigating a specific population with a higher prevalence of NMPOU or a study with a larger sample size should be undertaken to investigate some of the weaker associations between NMPOU and predictors such as region and income. Despite the limitation of sample size, we were able to obtain significant associations that have been observed previously in other studies. (25-28)

Obtaining population estimates of NMPOU by means of telephone surveys will lead, in most cases, to an undercoverage of NMPOU. (12,14) Undercoverage of NMPOU cannot be ignored since accurate prevalence estimates of NMPOU in populations are necessary for interventions to be effectively targeted at this growing epidemic. (2) In the future, alternative survey designs, such as personal interviews and better measures of NMPOU, are imperative. Despite these limitations and the risk of underestimation, NMPOU was found to be relatively prevalent in Ontario, with approximately 1 in 30 adults (380,000) engaging in NMPOU in the previous 12 months.

NMPOU is a rising epidemic in Canada and abroad. Our study suggests that all types of PO use, including non-medical uses, are similarly prevalent across socio-demographic strata in Ontario. New prevention strategies and health policies for NMPOU that address all socio-demographic groups will have to be implemented. Clearly, focusing on street drug users and their PO use and NMPOU will no longer be sufficient. (34)

Conflict of Interest: None to declare.

Received: September 4, 2010

Accepted: May 23, 2011

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Kevin D. Shield, MHSc, [1,2] Anca Ialomiteanu, MSc, [1] Benedikt Fischer, PhD, [1,3,4] Robert E. Mann, PhD, [1,4] Jurgen Rehm, PhD [1,2,4-6]

Author Affiliations

[1.] Centre for Addiction and Mental Health (CAMH), Toronto, ON

[2.] Institute of Medical Science, University of Toronto, Toronto, ON

[3.] Centre for Applied Research in Mental Health and Addictions, Simon Fraser University, Faculty of Health Sciences, Vancouver, BC

[4.] Dalla Lana School of Public Health, University of Toronto, Toronto, ON

[5.] Department of Psychology, University of Toronto, Toronto, ON

[6.] Institute for Clinical Psychology and Psychotherapy, Technische Universitat Dresden, Dresden, Germany

Correspondence: Kevin D. Shield, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Tel: 647-204-7323, Fax: 416-260-4146, E-mail: kevin.shield@utoronto.ca

Sources of Funding: Drs. Fischer and Rehm acknowledge funding support from a CIHR Team Grant (#SAF195814) as well as from the Ontario Ministry of Health and Long-Term Care. Dr. Fischer acknowledges support from a CIHR/PHAC Research Chair in Applied Public Health (#CPP85657), and from a Michael Smith Foundation for Health Research (MSFHR) Senior Scholar Award.

Table 1. Percentage Reporting Use of Prescription Opioid Pain Relievers
During the Previous 12 months, Ontarians, Aged 18+, CAMH Monitor,
2008-2009

                                         N    Any Use of PO

Total Sample                          2030     21.3
                                              (19.1, 23.4)
Gender                                        NS
  Men                                  896     19.9
                                              (16.9, 22.9)
  Women                               1134     22.7
                                              (19.6, 25.9)
Age (years)                                   NS
  18-29                                189     18.4
                                              (12.1, 24.7)
  30-54                                932     21.1
                                              (18.1, 24.1)
  55+                                  844     24.2
                                              (20.8, 27.6)
Region                                        NS
  Toronto                              317     20.9
                                              (15.8, 26.0)
  Rest of Ontario                     1713     21.3
                                              (19.0, 23.7)
Income                                        NS
  <$30,000                             250     23.2
                                              (17.0, 29.3)
  $30,000-$79,999                      644     23.1
                                              (19.2, 26.8)
  $80,000+                             619     19.6
                                              (16.1, 23.2)
  Not stated                           517     20.8
                                              (16.2, 25.4)
Daily cigarette smoking                       NS
  Yes                                  399     24.4
                                              (18.9, 29.6)
  No                                  1627     20.6
                                              (18.8, 29.6)
Weekly binge drinking                         NS
  Yes                                  133     19.7
                                              (11.9, 27.5)
  No                                  1883     21.4
                                              (19.2, 23.7)
Cannabis use                                  NS
  Yes                                  206     24.2
                                              (17.1, 31.3)
  No                                  1810     20.8
                                              (18.6, 23.0)
Psychological distress                        ***
(GHQ 3+)
  Yes                                  284     37.3
                                              (30.0, 44.6)
  No                                  1743     18.8
                                              (16.7, 21.0)

                            Any Non-medical   Used PO to
                            Use of PO         Get High

Total Sample                 2.0               0.5
                            (1.2, 2.8)        (0.0, 1.0)
Gender                      NS                NS
  Men                        2.4               0.8 ([dagger])
                            (1.0, 3.7)        (0.0, 1.7)
  Women                      1.6               0.2 ([dagger])
                            (0.8, 2.5)        (0.0, 0.5)
Age (years)                 NS
  18-29                      3.5               1.81
                            (0.4, 6.6)        (0.0, 4.4)
  30-54                      2.1               0.11
                            (1.1, 3.2)        (0.0, 0.3)
  55+                        1.0               0.31
                            (0.3, 1.7)        (0.0, 0.6)
Region                      NS                NS
  Toronto                    1.9               0.2 ([dagger])
                            (0.2, 3.7)        (0.0, 0.4)
  Rest of Ontario            2.0               0.6 ([dagger])
                            (1.1, 2.9)        (0.0, 1.0)
Income                      NS                NS
  <$30,000                   1.71              0.31
                            (0.0, 3.5)        (0.0, 1.0)
  $30,000-$79,999            2.51              0.2 ([dagger])
                            (1.1, 3.9)        (0.0, 0.3)
  $80,000+                   1.71              0.31
                            (0.6, 2.8)        (0.0, 0.5)
  Not stated                 1.91              1.11
                            (0.0, 3.9)        (0.0, 2.1)
Daily cigarette smoking     NS                **
  Yes                        4.0 ([dagger])    1.71
                            (1.0, 7.0)        (0.0, 4.1)
  No                         1.51              0.2 ([dagger])
                            (0.9, 7.0)        (0.0, 0.4)
Weekly binge drinking       NS                NS
  Yes                        4.0 ([dagger])    1.41
                            (0.6, 7.4)        (0.0, 3.5)
  No                         1.91              0.4 ([dagger])
                            (1.0, 2.7)        (0.0, 0.9)
Cannabis use                ***               ***
  Yes                        6.31              2.71
                            (2.0, 10.7)       (0.0, 6.2)
  No                         1.01              0.11
                            (0.2, 1.8)        (0.0, 0.3)
Psychological distress      ***               ***
(GHQ 3+)
  Yes                        7.51              2.41
                            (3.1, 11.9)       (0.0, 5.8)
  No                         1.21              0.2 ([dagger])
                            (0.6, 1.7)        (0.0, 0.4)

Notes: * p<0.05; ** p<0.01; *** p<0.001; CI = 95% confidence interval;
NS - no significant difference; ([dagger]) Estimate unstable (interpret
with caution) or suppressed due to high sampling variability.

Definitions: "Any use of pain relievers" defined as reporting any use
in the previous 12 months; "Any non-medical use of pain relievers"
defined as reporting use "to get high", obtained "from a prescription
written for someone else" or bought from someone else or obtained
"from any other source"; "Used pain relievers to get high" defined as
reporting use to get high in the previous 12 months.

Table 2. Percentage Reporting Any Non-medical Use of Prescription
Opioid Pain Relievers During the Previous 12 Months by Gender,
Ontarians, Aged 18+, CAMH Monitor, 2008-2009

                       Any Non-medical Use of POs

                                  Men

                       N                 %

Total Sample           896                2.4 ([dagger])
                                         (1.0, 3.7)
Age (years)                              NS
  18-29                100                4.9 ([dagger])
                                         (0.0, 10.1)
  30-54                420                2.3 ([dagger])
                                         (0.8, 3.9)
  55+                  356                0.8 ([dagger])
                                         (0.0, 1.8)
Region                                   NS
  Toronto              138                2.5 ([dagger])
                                         (0.0, 5.4)
  Rest of Ontario      758                2.3 ([dagger])
                                         (0.8, 3.8)
Income                                   NS
  <$30,000             87                 1.2 ([dagger])
                                         (0.0, 3.0)
  $30,000-$79,999      289                2.4 ([dagger])
                                         (0.4, 4.4)
  $80,000+             329                2.2 ([dagger])
                                         (0.6, 3.9)
  Not stated           191                2.9 ([dagger])
                                         (0.0, 6.9)
Cigarette smoking                        **
  Yes                  206                6.5 ([dagger])
                                         (1.6, 11.3)
  No                   690                1.2 ([dagger])
                                         (0.3, 2.1)
Weekly binge drinking                    NS
  Yes                  106                4.2 ([dagger])
                                         (0.3, 8.1)
  No                   781                2.1 ([dagger])
                                         (0.7, 3.5)
Cannabis use                             ***
  Yes                  135                8.3 ([dagger])
                                         (2.3, 14.4)
  No                   755                1.0 ([dagger])
                                         (0.2, 1.8)
Psychological distress (GHQ 3+)          ***
  Yes                  106               14.0 ([dagger])
                                         (4.1, 23.9)
  No                   789                1.0 ([dagger])
                                         (0.3, 1.7)

                       Any Non-medical Use of POs

                                 Women

                       N                 %

Total Sample           1134               1.6 ([dagger])
                                         (0.8, 2.5)
Age (years)                              NS
  18-29                89                 1.9 ([dagger])
                                         (0.0, 4.6)
  30-54                512                1.9 ([dagger])
                                         (0.5, 3.3)
  55+                  488                1.2 ([dagger])
                                         (0.2, 2.1)
Region                                   NS
  Toronto              179                1.4 ([dagger])
                                         (0.0, 3.4)
  Rest of Ontario      955                1.7 ([dagger])
                                         (0.7, 2.7)
Income                                   NS
  <$30,000             163                2.0 ([dagger])
                                         (0.0, 5.0)
  $30,000-$79,999      355                2.6 ([dagger])
                                         (0.6, 4.5)
  $80,000+             290                1.1 ([dagger])
                                         (0.0, 2.3)
  Not stated           326                1.2 ([dagger])
                                         (0.0, 2.6)
Cigarette smoking                        NS
  Yes                  194                1.9 ([dagger])
                                         (0.9, 2.9)
  No                   937                0.3 ([dagger])
                                         (0.0, 1.0)
Weekly binge drinking                    NS
  Yes                  27                 3.1 ([dagger])
                                         (0.0, 9.3)
  No                   1102               1.6 ([dagger])
                                         (0.7, 2.5)
Cannabis use                             NS
  Yes                  71                 1.9 ([dagger])
                                         (0.0, 2.5)
  No                   1055               1.6 ([dagger])
                                         (0.7, 2.5)
Psychological distress (GHQ 3+)          NS
  Yes                  178                3.2 ([dagger])
                                         (0.7, 5.8)
  No                   954                1.3 ([dagger])
                                         (0.4, 2.3)

Notes: * p<0.05; ** p<0.01; *** p<0.001; CI = 95% confidence interval;
NS - no significant difference; ([dagger]) Estimate unstable (interpret
with caution) or suppressed due to high sampling variability.

Definitions: "Any use of pain relievers" defined as reporting any use
in the previous 12 months; Any non-medical use of pain relievers
defined as reporting use "to get high", obtained "from a prescription
written for someone else" or "bought from someone else" or obtained
"from any other source"; "Used pain relievers to get high" defined as
reporting use to get high in the previous 12 months.

Table 3. Logistic Regression Models Predicting Non-Medical Use of
Prescription Opioid Pain Relievers During the Previous 12 Months,
Ontarians, Aged 18+, CAMH Monitor, 2008-2009

                            Non-medical Prescription Opioid
                            Use ([dagger])

                            Men (N=858)

                            Step 1

                            OR           (95% CI)

Age (ref. = 55+)
  18-29                     6.65         (1.55, 28.50)
  30-54                     3.68         (1.01, 13.47)
Toronto                     1.06         (0.30, 3.75)
(ref. = Rest of Ontario)
Income ([double dagger])
(ref. = <$30,000)
  $30,000-79,999            1.08         (0.22, 5.30)
  $80,000+                  0.79         (0.16, 3.94)
  Not stated                0.37         (0.05, 2.74)
Cigarette smoking
(ref. = no)
Weekly binge drinking
(ref. = no)
Cannabis use (ref. = no)
Psychological distress
(ref. = no)
Odds of non-medical         0.01 **
prescription opioid use
for an individual who is
in all reference
categories
Hosmer & Lemeshow test      19.39, p=0.02

                            Non-medical Prescription Opioid
                            Use ([dagger])

                            Men (N=858)

                            Step 2

                            OR           (95% CI)

Age (ref. = 55+)
  18-29                     3.27         (1.27, 16.58)
  30-54                     2.49         (0.64, 9.74)
Toronto                     1.18         (0.30, 4.65)
(ref. = Rest of Ontario)
Income ([double dagger])
(ref. = <$30,000)
  $30,000-79,999            2.12         (0.36, 12.34)
  $80,000+                  1.51         (0.27, 8.61)
  Not stated                0.57         (0.07, 4.77)
Cigarette smoking           2.29         (0.83, 6.32)
(ref. = no)
Weekly binge drinking       0.88         (0.42, 4.13)
(ref. = no)
Cannabis use (ref. = no)    4.64         (1.60, 13.48)
Psychological distress      7.55         (2.87, 19.88)
(ref. = no)
Odds of non-medical         0.00 ***
prescription opioid use
for an individual who is
in all reference
categories
Hosmer & Lemeshow test      17.2, p=0.51

                            Non-medical Prescription Opioid
                            Use ([dagger])

                            Women (N=1070)

                            Step 1

                            OR           (95% CI)

Age (ref. = 55+)
  18-29                     1.61         (0.32, 8.10)
  30-54                     1.44         (0.53, 3.96)
Toronto                     1.03         (0.30, 3.60)
(ref. = Rest of Ontario)
Income ([double dagger])
(ref. = <$30,000)
  $30,000-79,999            1.14         (0.29, 4.43)
  $80,000+                  0.63         (0.13, 3.00)
  Not stated                0.69         (0.15, 3.14)
Cigarette smoking
(ref. = no)
Weekly binge drinking
(ref. = no)
Cannabis use (ref. = no)
Psychological distress
(ref. = no)
Odds of non-medical         0.02 ***
prescription opioid use
for an individual who is
in all reference
categories
Hosmer & Lemeshow test      18.6, p=0.69

                            Non-medical Prescription Opioid
                            Use ([dagger])

                            Women (N=1070)

                            Step 2

                            OR           (95% CI)

Age (ref. = 55+)
  18-29                     1.85         (0.35, 9.73)
  30-54                     1.38         (0.49, 3.91)
Toronto                     1.17         (0.33, 4.15)
(ref. = Rest of Ontario)
Income ([double dagger])
(ref. = <$30,000)
  $30,000-79,999            1.06         (0.27, 4.19)
  $80,000+                  0.69         (0.14, 3.41)
  Not stated                0.71         (0.15, 3.31)
Cigarette smoking           0.18         (0.02, 1.45)
(ref. = no)
Weekly binge drinking       3.62         (0.41, 31.78)
(ref. = no)
Cannabis use (ref. = no)    0.52         (0.06, 4.32)
Psychological distress      4.21         (1.61, 11.00)
(ref. = no)
Odds of non-medical         0.01 ***
prescription opioid use
for an individual who is
in all reference
categories
Hosmer & Lemeshow test      18.1, p=0.07

* p<0.05; ** p<0.01; *** p<0.001; CI = 95% confidence interval;
([dagger]) at least once in the previous 12 months;
([double dagger]) Canadian dollars; ref. = reference category.