Factors related to the use of topical vs. oral NSAIDs for sprains, strains, and contusions in a senior population

Abstract

Background: Research to date on sprains, strains, and contusions has focused mainly on the analysis of sports-related injuries, occupational injuries, injuries resulting from automobile accidents, and severe injuries that result in inpatient hospital stays. Little is known about real-world acute sprains, strains, and contusions in an aging population. Patients may be treated with over-the-counter, oral, non-steroidal anti-inflammatory drugs (NSAIDs) for acute sprains, strains, and contusions or may require the use of prescription NSAIDs. For sprains, strains, and contusions treated with prescription NSAIDs, the choice of topical administration or oral administration likely depends on a number of factors such as age and comorbid conditions.

Objectives: The objective of the study was to identify factors associated with the use of a prescription topical NSAID or a prescription oral NSAID for the treatment of sprains, strains, and contusions among patients aged 65-89 years enrolled in the Medicare Advantage with Prescription Drug plan.

Methods: The study sample was selected from the Humana Research Database (Louisville, KY, USA). Study subjects were identified as patients enrolled in Medicare Advantage with Prescription Drug plans, aged 65-89 years, having a medical claim with an International Classification of Diseases, Ninth Revision, Clinical Modification indicative of an acute sprain, strain, and contusion between 1 January, 2010 and 31 March, 2014 (identification period). The date of the first claim was considered the index date, and subjects were required to have 12 months of continuous enrollment before the index date and a minimum of 3 months continuous enrollment after the index date. Prescription NSAID use during the 3 months after the index sprain, strain, and contusion diagnosis was required for study inclusion and was identified based on a pharmacy claim for a topical or an oral NSAID. Patients with prescription NSAID use leading up to the sprains, strains, and contusions were excluded. Potential factors related to the use of a topical vs. oral NSAID were identified using stepwise logistic regression with backward elimination.

Results: After applying the inclusion and exclusion criteria, 42,283 patients were prescribed an oral or topical NSAID (39,294 oral; 2989 topical) within 3 months of the index sprain, strain, and contusion diagnosis. After applying stepwise logistic regression, and retaining variables with statistically significant parameter estimates (p < 0.05), use of topical NSAIDs was higher among female individuals [odds ratio and 95% confidence interval = 1.34 (1.24-1.45)], and appeared to increase with age [odds ratio = 1.04 (1.04-1.05)]. Topical NSAID use was lower in the Midwest region [odds ratio = 0.85 (0.77-0.94)] in comparison to the Southern region. Clinical factors associated with topical NSAID use included Elixhauser Comorbidity Index score [odds ratio = 1.06 (1.04-1.09)], medication burden [odds ratio = 1.06 (1.04-1.08), pill burden [odds ratio = 1.02 (1.01-1.03), specific comorbid conditions, including site-specific osteoarthritis of the upper arm [odds ratio = 2.34 (1.19-4.60)], ankle/foot [odds ratio = 1.46 (1.14-1.87)], or lower leg [odds ratio = 1.21 (1.07-1.36)], myofascial pain [odds ratio = 1.31 (1.21-1.42)], gastrointestinal/hepatic disorders [odds ratio = 1.15 (1.05-1.25)], systemic/central pain [odds ratio = 1.12 (1.01-1.23)], and cataracts [odds ratio = 1.10 (1.02-1.20)]. Conversely, a diagnosis of diabetes mellitus was related to use of an oral NSAID rather than a topical NSAID [odds ratio = 0.86 (0.78-0.94)]. Diagnosis of the index sprain, strain, and contusion in an emergency department instead of a physician's office was also associated with oral NSAID use [odds ratio = 0.42 (0.37-0.47)].

Conclusions: Topical NSAIDs were used less often than oral NSAIDs following a sprain, strain, or contusion. Age, medication burden, pill burden, evidence of gastrointestinal disorder, and evidence of certain pain-related conditions were significant factors associated with topical NSAID as opposed to oral NSAID use. In comparison to oral NSAIDs, topical NSAIDs were more likely to be prescribed in a physician's office than an emergency department, possibly because a patient's physician has a better understanding of the patient's concomitant medications and comorbidities. Although topical NSAIDs were more likely to be used than oral NSAIDs in patients with gastrointestinal disorders, the use of oral NSAIDs among patients with gastrointestinal bleeding was substantial.