A real-world database analysis of the prevalence of pain medication use in the United States

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In 2022, nearly 40% of adults in the United States (102M people) experienced pain requiring treatment with prescription medication—80M and 29M with acute or chronic pain, respectively.

Abstract

Introduction:

Pain is a common and burdensome condition associated with significant health care costs and patient morbidity in the United States, yet limited pain prevalence data exists.

Objectives:

Provide national-level prevalence estimates of acute and chronic pain requiring management with prescription medication in the United States. Examine medication treatment patterns for the overall pain populations and a subset of patients with peripheral neuropathic pain (PNP).

Methods:

This study used a retrospective cross-sectional design that identified adults receiving treatment for pain in 2022 in the MarketScan Commercial and Medicare Supplemental and the Premier Healthcare Databases. Pain prevalence and medication use were analyzed and extrapolated to the United States population using standardized prevalence estimation methods.

Results:

Results suggest that approximately 102.1 million (M) people in the United States received prescription pain medication in 2022. Approximately 28.7M people received prescription medications for chronic pain, of which 11.1M (39%) had PNP conditions. Most patients with chronic pain used prescription nonsteroidal anti-inflammatory drugs (NSAIDs; 51%), anticonvulsants (44%), opioids (41%), and antidepressants (40%). Anticonvulsant use was more prominent in PNP (62% of patients had ≥1 prescription). Acute pain was estimated to affect 80.2M adults in the United States; 46.2M people with pain medication administered in-hospital, 43.5M filling prescription pain medications and 9.4M in both settings. Among all acute pain patients, 48% and 42% had evidence of opioid and NSAID use, respectively. Approximately 6.8M patients with chronic pain also experienced an acute pain event in-hospital.

Conclusion:

Findings show pain, pain medication use, and opioid-use in particular, are highly prevalent in the United States.

1. Introduction

Pain is one of the most common reasons patients in the United States seek medical care and is associated with significant economic burden and patient morbidity.^3,6,14,18 Although there are varying definitions of pain described in published literature and used in clinical practice, the distinctions between acute and chronic pain are generally well established and widely accepted. Chronic pain is defined by the International Association for the Study of Pain (IASP) as persistent or recurrent pain that lasts for ≥3 months.¹⁶ Acute pain is typically characterized as pain from an inciting event or stimulus that occurs suddenly and resolves when the underlying cause is treated or healed, generally within a period of 3 months or less.^4,15

Estimates of pain prevalence in the United States vary widely in the literature. The prevalence of chronic pain in adults in the United States is estimated to range from approximately 50 to 100 million.^6,9,12,18 These estimates vary based on definitions, methodologies, and date of analysis.^6,9,12,18 Little evidence exists regarding the prevalence of acute pain in the United States.

Pain may be managed pharmacologically with nonopioids and opioids, used alone or in combination.⁸ Nonopioids include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, antiepileptics, and local anesthetics, with one study showing NSAIDs and antidepressants to be the most commonly prescribed nonopioids among patients with chronic pain.^8,10 Treatment guidelines recommend using nonopioid treatment options, whenever possible, to minimize opioid use.^4,5 Although effective in managing pain, opioids pose tolerability concerns and carry risk of misuse and addiction, potentially increasing the burden on both patients and society.⁴

Peripheral neuropathic pain (PNP) is a particularly burdensome form of chronic pain caused by a lesion or disease of the peripheral somatosensory nervous system,¹³ which may be challenging to treat or manage because of underlying pathophysiological mechanisms of the disease. Studies outside the United States have shown that neuropathic pain, including PNP, is associated with a high degree of patient burden and health care resource utilization, with a substantial portion of direct patients' health care costs spent on medication.⁷ Data on the use of pain medication for managing PNP in the United States remain limited.

Given the variability and limitations in existing data, this study aimed to provide national-level estimates of prevalence of acute and chronic pain requiring management with prescription medication, and to examine medication treatment patterns for the overall acute and chronic pain populations, including the subgroup of patients with PNP in the United States.

2. Methods

2.1. Overview and study design

This was a retrospective cross-sectional study using 2 nationally representative data sets to provide an objective, complementary approach to evaluating the prevalence of acute and chronic pain in the United States, using prescription pain medication use to identify the population. Medication utilization and trends for the treatment of acute and chronic pain were examined in the 2 health care databases during a 1-year study period—from January 1, 2022 to December 31, 2022 (inclusive). Cohort outcomes were then extrapolated to the United States population using standardized prevalence estimation methods.

2.2. Databases

The Premier Healthcare Database was used to identify acute pain medication use occurring in a hospital inpatient or outpatient setting. Premier data provide real-world insights from 1310 health care facilities across the United States, accounting for 25% of annual discharges from hospital facilities. Chargemaster data were used to identify medications administered in hospitals. The MarketScan^® Commercial and Medicare Supplemental Databases were used to identify the use of acute or chronic pain medications outside of the hospital, specifically prescription pain medications filled at retail pharmacies or through mail-order programs. The MarketScan databases represent the health services of approximately 37 million employees, dependents, and retirees in the United States with primary or Medicare coverage through privately insured fee-for-service, point-of-service, or capitated health plans.

2.3. Patient population

The eligible population included adult patients (age ≥18 years) who used prescription pain medications of interest in the study databases during the 1-year study period, either administered in a hospital setting or filled at a pharmacy. Patient at-home use of over-the-counter pain medication was not captured in the study databases and therefore was not considered in this analysis. Patients in the MarketScan database were required to have a full year of continuous insurance and pharmacy coverage to ensure full capture of prescription medication use. This was not an applicable requirement in the Premier database, given the lack of patient enrollment data. This was a retrospective, anonymized claims analysis, and no informed consent was required.

Based on IASP definitions for chronic and acute pain,^13,16 patients with ≥3 months of continuous or recurrent use of prescription pain medication were classified as chronic pain patients, whereas those with <3 months of use were classified as acute pain patients, based on total days' supply within the study period. Pain medications considered in the analysis included prescription medications routinely used to treat pain^5,8: opioids, NSAIDs, anticonvulsants, local anesthetics, and serotonin and norepinephrine reuptake inhibitor (SNRI) antidepressants, and other nonopioid analgesics not otherwise classified (eg, acetaminophen). All routes of medication administration, including oral, parenteral, and topical, were considered for identification of the chronic pain cohort. Acute pain identification was based on nonparenteral medication use, as to not misclassify short-term parenteral medications used intraoperatively as pain management. Use of anticonvulsants and antidepressants were only considered for chronic pain if the patient had a diagnosed chronic pain condition during the study period, to avoid identifying patients using these medications for nonpain conditions (eg, anticonvulsant use for seizure conditions, antidepressants for depression). The identification of acute pain did not include the use of antidepressants and included only pregabalin and gabapentin for anticonvulsants.

Additional details on the study methodology are provided in the Supplement, including Table S1, http://links.lww.com/PR9/A375, which lists all pain medications used to identify acute and chronic pain patients, and Figures S1 and S2, http://links.lww.com/PR9/A375 which include details on sample selection criteria applied in the MarketScan and Premier databases, respectively.

2.4. Subgroups

In addition to examining the acute and chronic pain cohorts separately, study outcomes were examined by medication class, by underlying pain condition for the chronic pain cohort, and by medical setting and clinical indication for the acute pain cohort.

Chronic pain conditions were aligned with IASP classifications¹⁶ and included chronic primary pain and 6 other subgroups of chronic secondary pain, including PNP, central neuropathic pain, musculoskeletal pain, major cancer-related pain, headache and orofacial pain, and visceral pain. PNP was further categorized to include the following conditions: compression neuropathy, diabetic neuropathy, nondiabetic small fiber neuropathy, postherpetic neuropathy, radiculopathy, traumatic neuropathy, trigeminal neuropathy, and other peripheral neuropathy. Patients with chronic pain medication use were classified by pain condition based on diagnosis codes in the medical claims. See Supplement Table S2, http://links.lww.com/PR9/A375 for the list of chronic pain conditions.

Acute pain medication use was classified by medical setting as follows: hospital inpatient, hospital outpatient, discharge-related prescription, and all other retail prescriptions. Hospital setting was determined based on the Premier encounter location; the outpatient setting included visits to emergency departments, ambulatory surgery centers, and alternative sites of care. Pain medication prescriptions from the MarketScan database were classified as discharge if they were filled within 30 days of a medical encounter occurring in a hospital-based inpatient or outpatient setting.

Validated classification algorithms published by the Agency for Healthcare Research and Quality (AHRQ) were used to identify the possible clinical indications associated with acute pain prescriptions (eg, surgical procedures, injuries, or acute medical conditions). The Healthcare Cost and Utilization Project (HCUP) Surgery Flags Software for Services and Procedures was used to identify recent surgical procedures, and the Clinical Classification Software was used to identify recent medical diagnoses.^1,2 These were both applied to medical encounters that occurred within one month of an acute pain prescription fill, or during the hospital admission which pain medication was administered.

2.5. Extrapolations

Estimates of prevalence were generated for the MarketScan acute and chronic pain cohorts by comparing the number of patients meeting eligibility criteria to the number of patients in the eligible study population (adult patients with continuous insurance and pharmacy coverage in the study period). Prevalence estimates were generated by gender and age groupings because these demographics are known to influence pain diagnoses and treatment patterns. Age- and gender-specific cohort prevalence estimates were then multiplied by the 2022 United States Census population counts, using the same age and gender strata, to generate population estimates.¹⁷

An alternate extrapolation method was used for the Premier analysis because the eligible study population could not be sized because of lack of enrollment data. Results from the Premier analysis for acute pain in a hospital inpatient setting were extrapolated to national-level estimates using projection weights provided by Premier. The projections weights are provided on the hospital-level and are based on Annual Hospital Association (AHA) Annual Survey data on hospital characteristics including geographic region, ownership, population size served, number of beds, and teaching status. Given Premier projection weights are only available for the inpatient discharge data set, extrapolations for the outpatient hospital setting required additional assumptions. The ratio of patients with outpatient to inpatient hospital encounters in the Premier database during the 1-year study period (6.2) was combined with the estimate of the total number of patients with inpatient hospital encounters in the United States generated using the projection weights provided by Premier (24.5 million); this generated an estimate of the number of people with hospital outpatient encounters in the United States in 2022 (153 million). The prevalence of acute pain medication use observed in the hospital outpatient setting from Premier was then applied to this extrapolated estimate of hospital outpatient encounters.

Extrapolations were adjusted to account for the potential overlap in the studied populations (ie, patients with acute or chronic pain with prescription pain medication fills who also received pain medication in-hospital). Because this information was not available in a single study database (MarketScan databases do not include information on in-hospital medication use, Premier database does not include information on discharge prescriptions) and patient-level linking of the 2 de-identified study databases was not available, estimates were generated by combining independent summary information from the 2 databases. First, the proportion of the MarketScan acute and chronic pain cohorts who were hospitalized during the study period were summarized, stratified by age and gender. Separately, in the Premier data set, the proportion of hospital encounters involving administration of pain medications was estimated using the same age and gender strata. The estimated in-hospital pain medication use for the MarketScan acute and chronic pain cohorts were derived by multiplying the age- and gender-specific hospitalization rates from the claims data by corresponding proportion of in-hospital medication use from the Premier data.

3. Results

3.1. Sample selection and prevalence estimation

Among the 12.8 million adults with continuous insurance and pharmacy coverage in the MarketScan databases during the study year, 1.3 million met the selection criteria for chronic pain and 2.2 million met the inclusion criteria for acute pain. In addition, the analysis of the Premier database identified 5.1 million inpatient encounters and 7.6 million outpatient encounters in which pain medication was administered in 2022. Additional details on sample selection in the MarketScan and Premier databases are provided in Supplement Figures S1 and S2, http://links.lww.com/PR9/A375, respectively.

Estimates of the prevalence of chronic pain varied across age and gender strata—from 1.4% for males aged 18 to 24 years to 21.5% for females age ≥65 years. The overall age- and gender-adjusted estimate of prevalence of chronic pain was 11.0%. Similarly, estimates of prevalence of acute pain varied from 16.9% for males aged 18 to 24 years to 40.0% for females aged ≥65 years. The overall age- and gender-adjusted estimate of prevalence of acute pain was 30.7%.

3.2. Chronic pain prevalence

An estimated 28.7 million adults in the United States in 2022 required ≥3 months of prescription pain medication to address their chronic pain. The most common pain condition was musculoskeletal pain, which affected 79% of these adults (Table 1). Approximately 11.1 million adults (39% of the total chronic pain population) had evidence of a chronic PNP condition, with the most common condition being radiculopathy, affecting 6.8 million people. For adults with radiculopathy requiring prescription pain medication, the most common location was the lumbosacral area, which affected 5.5 million adults (81% of radiculopathy, 50% of chronic PNP, and 19% of all chronic pain). After radiculopathy, the most common PNP conditions were nondiabetic small fiber neuropathy and diabetic peripheral neuropathy, each estimated at 22% of the total United States chronic pain population.

Table 1.

Extrapolated estimate of the number of people in the United States in 2022 with chronic pain requiring management with prescription pain medication, by underlying pain condition.

Condition	Estimated number of people (million)	Proportion of total chronic pain population (%)
Chronic pain	28.7	100%
Musculoskeletal pain	22.7	79%
Visceral pain	16.3	57%
Other primary pain (including mechanism unknown)	13.4	47%
Peripheral neuropathic pain	11.1	39%
Radiculopathy	6.8	24%
Nondiabetic small fiber neuropathy	2.4	8%
Diabetic peripheral neuropathy	2.4	8%
Other peripheral neuropathy	1.2	4%
Compression neuropathy	1.1	4%
Postherpetic neuropathy	0.4	1%
Trigeminal neuropathy	0.3	1%
Traumatic neuropathy	0.1	<1%
Cancer-related pain	10.0	35%
Headache or orofacial	3.7	13%
Central neuropathic pain	0.8	3%

Based on prescription pain medication filled at a retail pharmacy. Groups are not mutually exclusive; patients could contribute to more than one of the listed pain conditions.

Approximately half of the adult chronic pain cohort had ≥1 prescription for an NSAID (51%), anticonvulsant (44%), opioid (41%), and antidepressant (40%), respectively. Comparatively, the most common pain prescriptions filled by people with PNP were anticonvulsants (62% of people with PNP had ≥1 prescription), opioids (52%), NSAIDs (51%) and antidepressants (37%) (Fig. 1). Treatment patterns were largely consistent across the PNP conditions, although anticonvulsant use was slightly more prevalent in diabetic peripheral neuropathy than lumbosacral radiculopathy (73% vs 60% of people had ≥1 prescription).

Figure 1.

Extrapolated estimate of prescription pain medication use in patients with chronic pain and chronic PNP conditions. *Patient counts by medication class are not additive as patients could receive, and contribute to, more than one medication class. M, million; NSAID, nonsteroidal anti-inflammatory drug; PNP, peripheral neuropathic pain.

Approximately 60% of people with chronic pain and 73% of people with chronic PNP had use of more than one prescription pain medication (identified by main ingredient only, not considering varying strengths or combinations) in the calendar year. Approximately 11% to 12% of those receiving only one prescription pain drug had use of an opioid.

3.3. Acute pain prevalence

An estimated 80.2 million adults in the United States in 2022 had acute pain requiring management with prescription pain medication for <3 months. Among this population, approximately 46.2 million (58%) people were estimated to have a hospital inpatient (19.6 million) or hospital outpatient (29.7 million) encounter during which medication was administered for acute pain management. Approximately 43.5 million (54%) people were estimated to have a prescription pain medication dispensed at a retail pharmacy; among these, 23.9 million people had a pain prescription associated with a recent hospital discharge. The overlap analysis suggests that approximately 9.4 million people receive pain medication in-hospital and also have prescription pain medication use. Overall, approximately 75% of acute pain patients begin their journey in health systems and hospitals—either with pain medication administered in-hospital or with an acute pain medication dispensed after hospital discharge.

The most common oral pain medications administered in hospital settings were nonopioid analgesics (28.4 million [62%] of acute pain hospital cohort had ≥1 administration) and opioids (21.8 million [47%]) (Fig. 2). Opioids were used more frequently in the hospital inpatient setting than the hospital outpatient setting (58% vs 39%, respectively). Comparatively, the most common prescription pain medications that patients filled in retail pharmacies were prescription NSAIDs (27.5 million [63%] of acute pain retail prescription cohort had ≥1 fill) and opioids (21.6 million [50%]) (Fig. 2). Opioids were the most frequently used discharge pain prescription, with 60% of patients with a discharge pain prescription filling an opioid. Overall, nearly 50%, or 38.7 million people with acute pain received an opioid, either administered during a hospital encounter or filled at a retail pharmacy.

Figure 2.

Extrapolated estimate of pain medication use in patients with acute pain by medical setting. *Patient counts by setting are not additive, as totals adjust for overlap of hospitalized patients who had prescription pain medication use. Patient counts by medication class also not additive as patients could receive, and contribute to, more than one medication class. M, million; NSAID, nonsteroidal anti-inflammatory drug.

Approximately two-thirds (67%; 13.2 million) of people receiving acute pain medication in a hospital inpatient setting, and one-third (31%; 9.1 million) of people receiving acute pain medication in a hospital outpatient setting, had a surgical encounter during the hospital stay. Approximately 30% (12.2 million) people receiving an acute pain prescription dispensed at a retail pharmacy had a recent hospital discharge during which a surgery was performed, including 9.5 million people with major surgery¹ and 2.7 million people with minor surgery.¹ The most common surgeries among acute pain patients in both settings (prescription, hospital) were operations on the musculoskeletal or digestive systems and obstetrical procedures; cardiovascular operations were also a common cause for acute pain medication use in a hospital inpatient setting.

3.4. Total pain prevalence estimates

This analysis suggests that there were approximately 102 million adults in the United States in 2022 with acute or chronic pain requiring management with prescription pain medication. This total reflects unique patients after addressing overlap between acute and chronic pain, which included 6.8 million patients with chronic pain who were estimated to also experience episodes of acute pain in the hospital setting.

4. Discussion

This retrospective cross-sectional study used 2 robust sources of national health care claims and hospital encounters data to provide a contemporary assessment of pain medication use in the United States. Our analysis estimated that 102 million unique adults in the United States experienced pain requiring treatment with prescription pain medication in 2022. This represents approximately 39% of the adult population. Among these patients, 28.7 million had chronic pain, of which 11.1 million had chronic PNP. Acute pain was estimated to affect 80.2 million people.

Our estimated prevalence of chronic pain reflects patients in the United States managing pain with prescription medications, which differed from other estimates previously reported in the literature. In 2010, the Institute of Medicine Committee on Advancing Pain Research, Care, and Education reported that approximately 100 million adults in the United States suffered from chronic pain; the study did not report the proportion of these patients managing pain with prescription medication.⁶ Two cross-sectional studies using the United States National Health Interview Survey estimated the prevalence of chronic pain in adults to be 50.2 million in 2019 and 51.6 million in 2021 based on direct-to-patient surveys in which patients reported having pain on most days or every day in the previous 3 months, without any specification on pain severity or method of treatment.^9,18 The differences in chronic pain prevalence are likely because of methodological differences, specifically the requirement for prescription pain medication use. Our study focused on real-world treatment patterns of prescription pain medication use in large nationally representative data sets. Patients with mild pain who managed symptoms without medication or with only over-the-counter pain medication were not captured in our analysis. Our study results, which required patients to have prescription pain medication use, are therefore more likely to reflect a population with moderate-to-severe pain. Inclusion of patients with mild pain would increase our prevalence estimates. In addition, survey studies rely on subjective reporting of pain severity and may not meet our stricter definition of prescription pain medication use for ≥3 months. Studies also report high discontinuation rates of pain medications, particularly in PNP, which would limit the inclusion of these patients from our study because of the 3-month prescription requirement. Therefore, our estimates of chronic pain should be considered conservative. Data on prevalence of acute pain in adults in the United States are lacking, therefore limiting comparisons with results observed in this current analysis.

The use of prescription medications for patients with chronic pain is common and widely varied, depending on a patient's disease history and clinical practices. The findings that NSAIDs and opioids were the most common treatments in patients with chronic pain are consistent with pain management practice guidelines and current clinical practice for chronic pain management.^4,11 Prescription nonopioids, including NSAIDs, are among the most common pain relief medications prescribed to patients with chronic pain in the United States.¹¹ However, the prevalence of opioid use in this study (45%) was higher than that reported in a previously published survey study of patients with chronic pain in the United States (13.5%).¹¹ This difference is again because of the study populations—unlike our study, the published survey study included all patients with chronic pain regardless of pain management strategy, more than half of which did not receive a prescription opioid or nonopioid and instead managed chronic pain with over-the-counter pain relievers and nonpharmacologic treatment options. Beyond the differences in populations, there may also be underreporting of opioid use by patients in health surveys, whereas in our study, using pharmacy and hospital records may reflect the real-world patterns of medication use more accurately. The high prevalence of opioid use estimated in this study highlights the need for careful considerations to balance the competing goals of managing pain effectively while avoiding the harmful effects of opioids, including opioid use disorder or overdose.^4,6 Findings from this study showed anticonvulsants were the most commonly prescribed treatment among patients with chronic PNP, which is consistent with published literature.⁷

5. Limitations

Limitations of this study include the classification of acute and chronic pain based on an algorithm adapted to administrative claims, which may not capture clinical nuance. In this study, medication use was used as a proxy for pain, which may not fully capture the clinical intent of prescribing. Some drugs included in the analysis, such as antidepressants or anticonvulsants, can be used for both pain management and nonpain indications. To mitigate this, the analysis required the presence of a chronic pain diagnosis code alongside medication use. However, misclassification is still possible, and medication use may have slightly overestimated the prevalence of pain treatment in the study population. Future work validating the claims-based algorithm against clinical records would strengthen this methodological approach.

Next, because linking of the 2 study databases was not available, several assumptions needed to be made to estimate the overlap in pain medication occurring both in the hospital and with prescription medication filled at a retail pharmacy. The indirect estimation approach used in this analysis assumes that the in-hospital pain medication utilization patterns in the 2 separate data sources are comparable. Any differences in the underlying population between the data sets may bias the estimates of overlap. In addition, the use of aggregated proportions prevents assessment of individual-level variation and may obscure important clinical or demographic factors influencing in-hospital medication use. Further research using linked administrative claims and hospital chargemaster databases to examine pain medication occurring in both settings could provide more robust estimation.

Finally, this study is subject to known limitations of database studies. Although 2 large databases were used and adjustments were made for available factors (age and gender in MarketScan, hospital characteristics in Premier), there may be other unmeasured variables—such as socioeconomic status, race/ethnicity, or regional variation—that could not be accounted for in the analysis and could influence the results. Furthermore, the use of an administrative claims database limited to individuals with commercial and Medicare coverage could generate bias results if rates of pain and pain medication use differ in Medicaid or uninsured populations. Future research using data sets with these populations represented may help address these gaps.

6. Conclusion

This study provides a comprehensive and robust assessment of the number of adults living in the United States with moderate-to-severe acute and chronic pain and underscores the burden of managing pain with prescription medications for tens of millions of Americans. Frequent use of opioids was observed across both the acute and chronic pain cohorts, highlighting the continued use of opioids to manage pain despite their side-effect profile and addictive potential.

Disclosures

A.L., A.M., and J.R. are employees of Vertex Pharmaceuticals and may own stock/stock options in the company.

Supplemental digital content

Supplemental digital content associated with this article can be found online at http://links.lww.com/PR9/A375.