Figure 2.

Trends in medication use among adult cough-related visits in office-based ambulatory care setting: 2003–2018 NAMCS. Abbreviations: NAMCS: National Ambulatory Medical Care Survey; NCHS: National Center for Health Statistics. ^a P_trend were adjusted for age, sex, race, and payment source. ^b Dextromethorphan indicates dextromethorphan-containing antitussives. ^c The weighted-estimate for gabapentinoid in 2003–2005 is unreliable based on NCHS’s recommendation. ^d The weighted-estimate of the denominator (i.e., adult cough-related office-based visits) for each time period in NAMCS is 183.7 million, 171.9 million, 179.7 million, 152.8 million, and 131.8 million for 2003–2005, 2006–2008, 2009–2011, 2012–2014, and 2015–2018, respectively.