Trends in Central Nervous System–Active Polypharmacy Among Older Adults Seen in Outpatient Care in the United States

With each new revision of the Beers Criteria, the list of psychotropic medications considered potentially inappropriate in the elderly has grown. Opioids have recently been included in a Beers measure of central nervous system (CNS) polypharmacy.¹ Prescribing related drug combinations also received increased regulatory attention when the US Food and Drug Administration recently ordered a black-box warning to alert patients of serious risks, including death, caused by opioids coprescribed with CNS depressants. While evidence builds concerning harms of CNS polypharmacy, little is known about the trends in relevant prescribing practices.

This analysis used data from the 2004 through 2013 National Ambulatory Medical Care Survey (NAMCS), an annual survey of office-based physicians.² We limited our analysis to patients aged 65 years or older (n = 97 910). Because this research is on publicly available, deidentified data, the University of Michigan Medical School institutional review board did not require approval. An outpatient visit met Beers CNS polypharmacy criteria if 3 or more of the following medications were initiated or continued: antipsychotics, benzodiazepines, nonbenzodiazepine benzodiazepine receptor agonists, tricyclic antidepressants, selective serotonin reuptake inhibitors, and opioids. We recorded up to 3 visit diagnoses and included NAMCS-collected information such as chronic medical conditions, whether psychotherapy was provided or ordered, whether stress management or other mental health counseling services were provided or ordered, and time spent with physician.

We used logistic regression to assess time trends in polypharmacy. For the most recent period (2011-2013), difference-in-proportion tests were used to compare visit characteristics by polypharmacy type. Analyses were conducted in Stata, version 13.1 (StataCorp LLC), using 2-sided tests (α = .05).

Data were collected from January 2004 to December 2013. Data analysis took place from October 7, 2016, to October 28, 2016.

Between 2004 and 2013, annual polypharmacy visits by adults 65 years or older increased from 1.50 million (95% CI, 1.12-1.87 million) to 3.68 million (95% CI, 3.23-4.13 million), rising from 0.6% to 1.4% of visits (adjusted odds ratio [AOR], 3.12; 95% CI, 2.28-4.28; P < .001) (Table 1). Among demographic groups, the largest increase in CNS polypharmacy was among rural visits (AOR, 4.99; 95% CI, 2.67-9.33; P < .001). Additionally, CNS polypharmacy increased among visits with no mental health or pain diagnoses (AOR, 2.65; 95% CI, 1.65-4.27; P < .001).

Women and rural patients accounted for 68.1% and 16.6% of CNS polypharmacy visits, compared with 55% and 10.5% of nonpolypharmacy visits (P < .001 for both comparisons) (Table 2). While mental health or pain diagnoses were more common among the polypharmacy group, 45.9% of the polypharmacy visits included neither mental health nor pain diagnoses. A small minority of polypharmacy visits included psychotherapy (5.3%) or stress management (6.7%). There were no significant demographic differences between polypharmacy visits with and without opioids. Polypharmacy encounters without opioids were more likely to include an anxiety or a depression diagnosis but were less likely to include a pain diagnosis (15.3% vs 38.5%; P = .01).

From 2004 to 2013, CNS polypharmacy more than doubled. While it was most common at visits with anxiety, insomnia, or depression, there was not a significant increase at such visits. By contrast, polypharmacy significantly increased for patients with a pain diagnosis, occurring in the context of the overall growth in opioid prescribing. Visits without pain, insomnia, or other mental health diagnoses accounted for nearly half (45.9%) of CNS polypharmacy visits and grew significantly from 2004 to 2013.

Older adults have become more open to mental health treatment.³ Because of limited access to specialty care and a preference to receive treatment in primary care settings,⁴ it is unsurprising that mental health treatment has expanded in nonpsychiatric settings. The growth in polypharmacy in rural settings, where access to specialty mental health or pain care is particularly limited,⁵ is part of this broader trend.

This study has several limitations. First, NAMCS does not account for whether a medication is prescribed as needed, so regular use may have been overestimated. Second, NAMCS does not capture outcomes nor include nonphysicians. Nonresponse might introduce bias, but survey weights account for nonresponse to produce unbiased estimates.² Finally, our visit diagnoses were limited to 3, so prescribing without a diagnosis may have been overestimated. However, psychotropic use without a diagnosis has been described in other studies⁶ and thus is unlikely an artifact of NAMCS.

Corresponding Author: Donovan T. Maust, MD, MS, Department of Psychiatry, University of Michigan, 2800 Plymouth Rd, NCRC 016-222W, Ann Arbor, MI 48109 (maustd@umich.edu).

Correction: This article was corrected online on April 3, 2017, for a missing “MPH” degree for Dr Olfson.

Published Online: February 13, 2017. doi:10.1001/jamainternmed.2016.9225

Author Contributions: Dr Maust had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Maust, Gerlach, Blow, Olfson.

Acquisition, analysis, or interpretation of data: Maust, Gibson, Kales, Blow, Olfson.

Drafting of the manuscript: Maust, Gerlach, Kales.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Maust.

Obtained funding: Maust.

Administrative, technical, or material support: Blow.

Study supervision: Kales, Blow.

Conflict of Interest Disclosures: None reported.

Funding/Support: Dr Maust was supported by the Beeson Career Development Award Program (National Institute on Aging grant K08 AG048321, American Federation for Aging Research, The John A. Hartford Foundation, and The Atlantic Philanthropies).

Role of the Funder/Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.