Trends in Prescription Drug Use Among Adults in the United States From 1999 – 2012

Sarah Vo, Mercer University College of Pharmacy

The Centers for Disease Control and Prevention (CDC) reported that 48.7% (2009 – 2012) of the population in the United States (US) used at least one prescription drug in the past 30 days.  The CDC also reported that 10.7% (2009 – 2012) of the US population used five or more prescription drugs in the past 30 days. [1]

Prescription drugs are said to be a vital component of efforts to maintain or improve health.  The increase in new products and technologies, the number of people prescribed medications, and the number of prescriptions per user are considered to have contributed to increases in overall prescription drug spending. [2]

Drug utilization research helps compare the observed patterns of drug use for the treatment of a certain disease with current recommendations or guidelines.  It is considered to have the ability to determine the pattern or profile of drug use and the extent to which alternative drugs are being used to treat particular conditions. [3]

Title: Trends in Prescription Drug Use Among Adults in the United States From 1999 – 2012 [4]
Design Retrospective; N = 37,959
Objective To evaluate trends in prescription drug use among adults living in the United States (US)
Study Groups Noninstitutionalized US adults aged 20 years and older
Methods Data from seven National Health and Nutrition Examination Survey (NHANES) cycles were analyzed.

Participants were asked if they had taken prescription drugs over the prior 30 days.  If the participants did not provide a medication container, the medication name was given.  The interviewer entered medication names into prescription drug database (Lexicon Plus).

Duration 1999 – 2012
Primary Outcome Measure Within each NHANES cycle, use of prescription drugs in the prior 30 days was assessed overall and by drug class.  Temporal trends across cycles were evaluated.  Analyses were weighted to represent the US adult population.
Baseline Characteristics 1999 – 2000 (n = 4,861) 2001 – 2002 (n = 5,399) 2003 – 2004 (n = 5,029) 2005 – 2006 (n = 4,970) 2007 – 2008 (n = 5,930) 2009 – 2010 (n = 6,212) 2011 – 2012 (n= 5,558)
Age group, years
20 – 39 1,692 1,925 1,737 1,923 1,910 2,081 1,957
40 – 64 1,787 2,022 1,799 1,864 2,469 2,611 2,352
≥ 65 1,382 1,452 1,493 1,183 1,551 1,520 1,249
Sex
Women 2,600 2,867 2,617 2,587 3,021 3,210 2,819
Men 2,261 2,532 2,412 2,383 2,909 3,002 2,739
Results The response rate for adults aged 20 years and older was 73.6% and 84% of medications containers were seen by interviewers.

The final sample size was 37,959.

1999 – 2000 2011 – 2012
Use of any prescription drugs (%) 51 59
Overall Difference, 8%, [95% CI, 3.8& – 12%]; p < .001
Polypharmacy (use of ≥ 5 prescription drugs) (%) 8.2 15
Overall Difference, 6.6% [95% CI, 4.4% – 8.2%]; p < .001
Top 18 used drug classes: antihypertensive agents, antihyperlipidemic agents, antidepressants, prescription analgesics, antidiabetic agents, prescription proton-pump inhibitors, thyroid hormones, anxiolytics/ sedatives/ hypnotics, anticonvulsants, bronchodilators, antibiotics, antiarrhythmic agents, coagulation modifiers, muscle relaxants, H2 antagonists, prescription antihistamines, antiemetic/ antivertigo agents, and glucocorticoids.  Among the 18 drug classes used more than 2.5% of the population at any point over the study period. The prevalence of use increased in 11 drug classes including antihyperlipidemic agents, antidepressants, prescription proton-pump inhibitors, muscle relaxants, antidiabetic agents, anticonvulsants, bronchodilators, antihypertensive agents, prescription analgesics, anxiolytics/ sedatives/ hypnotics, and coagulation modifiers.
Adverse Events Common Adverse Events: not applicable
Serious Adverse Events: not applicable
Percentage that Discontinued due to Adverse Events: not applicable
Study Author Conclusions In this nationally representative survey, significant increases in overall prescription drug use and polypharmacy were observed.  These increases persisted after accounting for changes in the age distribution of the populations.  The prevalence of prescription drug use increased in the majority of, but not all, drug classes.

There were many limitations in this study.  The survey only included noninstitutionalized adults and did not include adults living in nursing homes.  This study should only be generalized to the community-dwelling US adult population.  Another limitation is that certain drugs may be in more than one class and some drugs may be taken for off-label use; therefore, the classifications of drugs do not perfectly align with the reasons for use.

This study provided a comprehensive picture of prescription drug use in the US adult population.  Prescription drug use was assessed via in-home interviews in which containers were seen for 84% of drugs, giving confidence to participants’ self-reported use.  There was a high response rate with NHANES which reduced concern for bias.

References

  1. Therapeutic Drug Use. The Centers for Disease Control and Preventionhttp://www.cdc.gov/nchs/fastats/drug-use-therapeutic.htm.  Updated May 14, 2015.  Accessed November 8, 2015.
  2. Bruen, B.K. (2002). States strive to limit Medicaid expenditures for prescribed drugs. Washington, DC: The Kaiser Commission on Medicaid and the Uninsured. Available at http://www.kff.org. Accessed November 8, 2015.
  3. Description of drug use patterns. The World Health Organizationhttp://apps.who.int/medicinedocs/en/d/Js4876e/2.2.1.html#Js4876e.2.2.1.  Published 2003.  Accessed November 8, 2015.
  4. Kantor ED, Rehm CD, Haas JS, Chan AT, Giovannucci EL. Trends in Prescription Drug Use Among Adults in the United States From 1999-2012. 2015;314(17):1818-1830. doi:10.1001/jama.2015.13766.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s