Adverse Selection? A Multi-Dimensional Profile of People Dispensed Opioid Analgesics for Persistent Non-Cancer Pain

<div><p>Objectives</p><p>This study investigates utilisation patterns for prescription opioid analgesics in the Australian community and how these are associated with a framework of individual-level factors related to healthcare use.</p><p>Methods</p><p>Self-reported demographic and health information from participants in the <i>45 and Up Study</i> cohort were linked to pharmaceutical claims from 2006–2009. Participants comprised 19,816 people with ≥1 opioid analgesic dispensing in the 12-months after recruitment to the cohort and 79,882 people not dispensed opioid analgesics. All participants were aged ≥45 years, were social security pharmaceutical beneficiaries, with no history of cancer. People dispensed opioid analgesics were classified as having acute (dispensing period <90 days), episodic (≥90 days and <3 ‘authority’ prescriptions for increased quantity supply) or long-term treatment (≥90 days and ≥3 authority prescriptions).</p><p>Results</p><p>Of participants dispensed opioid analgesic 52% received acute treatment, 25% episodic treatment and 23% long-term treatment. People dispensed opioid analgesics long-term had an average of 14.9 opioid analgesic prescriptions/year from 2.0 doctors compared with 1.5 prescriptions from 1.1 doctors for people receiving acute treatment. People dispensed opioid analgesics reported more need-related factors such as poorer physical functioning and higher psychological distress. Long-term users were more likely to have access-related factors such as low-income and living outside major cities. After simultaneous adjustment, association with predisposing health factors and access diminished, but indicators of need such as osteoarthritis treatment, paracetamol use, and poor physical function were the strongest predictors for all opioid analgesic users.</p><p>Conclusions</p><p>People dispensed opioid analgesics were in poorer health, reported higher levels of distress and poorer functioning than people not receiving opioid analgesics. Varying dispensing profiles were evident among people dispensed opioid analgesics for persistent pain, with those receiving episodic and long-term treatment dispensed the strongest opioid analgesics. The findings highlight the broad range of factors associated with longer term opioid analgesics use.</p></div

Rate-ratio (RR) of the association of variables (by Andersen-Newman model categories of Predisposing, Access, and Need) belonging to a category of opioid use (Acute, Episodic, Long-term – see Methods and Materials for details) with non-users as the reference group, each variable fully adjusted by all variables in this table.

1<p>Language other than English.</p>2<p>Quality of Life.</p>3<p>Medical-outcomes study physical function scale, values range from 0 (lowest physical function level) to 100 (highest physical function level.</p>4<p>Self-reported, in last 28 days.</p>5<p>Self-reported surgery within 2 years of baseline recruitment.</p

Characteristics of opioid analgesic dispensings, including mean number, mean time of opioid supply, mean number of prescribers, mean index of diversity of opioid prescribers (higher index = more prescribers and more variance in number of dispensings per prescriber), mean oral morphine equivalents per day during period of opioid dispensings, and co-dispensing of other medicines during period of opioid supply by treatment group (see methods for details).

<p>Characteristics of opioid analgesic dispensings, including mean number, mean time of opioid supply, mean number of prescribers, mean index of diversity of opioid prescribers (higher index = more prescribers and more variance in number of dispensings per prescriber), mean oral morphine equivalents per day during period of opioid dispensings, and co-dispensing of other medicines during period of opioid supply by treatment group (see methods for details).</p

Personal characteristics of individuals (n, (% of treatment group)) dispensed opioid analgesics, by treatment group (Acute – supply <90 days; Episodic – Supply ≥90 days, <3 increased quantity dispensings; Long-term – Supply ≥90 days, ≥3 increased quantitative dispensings).

1<p>Language other than English.</p>2<p>Household Income in Australian Dollars.</p>3<p>Quality of Life.</p>4<p>Medical-outcomes study physical function scale, values range from 0 (lowest physical function level) to 100 (highest physical function level.</p

Use of opioid analgesics by drug class and treatment group, with total morphine equivalent dose (/day across entire opioid supply period) for those dispensed type at least once.

<p>Use of opioid analgesics by drug class and treatment group, with total morphine equivalent dose (/day across entire opioid supply period) for those dispensed type at least once.</p

Participant flow according to inclusion and exclusions rules in this study.

<p>Participant flow according to inclusion and exclusions rules in this study.</p

Rate-ratio (RR) of the association of variables (by Andersen-Newman model categories of Predisposing, Access, and Need) belonging to an opioid analgesic treatment group (Acute, Episodic, Long-term – see Methods and Materials for details) with those not dispensed an opioid analgesic as the reference group, each variable adjusted for age and sex.

1<p>Language other than English.</p>2<p>Quality of Life.</p>3<p>Medical-outcomes study physical function scale, values range from 0 (lowest physical function level) to 100 (highest physical function level.</p>4<p>Self-reported, in last 28 days.</p>5<p>Self-reported surgery within 2 years of baseline recruitment.</p

Diagnosis, pharmacy and procedure codes used to identify history of specified conditions.

<p>Diagnosis, pharmacy and procedure codes used to identify history of specified conditions.</p

Results from multivariate Poisson regression models: impact of clinical and demographic characteristics on commencing different endocrine therapies between January 2004 and December 2010 for post-menopausal women with invasive breast cancer.

<p>Results from multivariate Poisson regression models: impact of clinical and demographic characteristics on commencing different endocrine therapies between January 2004 and December 2010 for post-menopausal women with invasive breast cancer.</p

Australian clinical guidelines for endocrine therapy use in women with hormone-dependent early breast cancer [12], [13].

<p>Australian clinical guidelines for endocrine therapy use in women with hormone-dependent early breast cancer <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084835#pone.0084835-National1" target="_blank">[12]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084835#pone.0084835-National2" target="_blank">[13]</a>.</p