Abstract

Introduction

Complex regional pain syndrome type 1 (CRPS-1) is a rare, chronic condition following injury without an identifiable nerve lesion. Pain and physical impairment can persist years after diagnosis.¹ CRPS-1 is not in the Social Security Administration Blue Book of impairments qualifying for disability but was added as a Medically Determinable Impairment (MDI) in 2024.² We examined diagnoses of mobility impairment and transition to presumptive Social Security Disability Insurance (SSDI) among patients after first CRPS-1 diagnosis.

Methods

We conducted a retrospective cohort analysis using Komodo Health's primarily claims-derived Healthcare Map®, a longitudinal and nationally representative health service utilization database with >330 million de-identified, insured US-patients. We identified incident CRPS-1 patients (ICD10 G90.5x) diagnosed 01/01/17-12/31/24, excluding those with open claims and CRPS-2/causalgia diagnosis (ICD10 G56.4x or G57.7x). Two reviewers adjudicated ICD10 codes in the 18 months after CRPS-1 diagnosis for those indicating impaired function/mobility/disability (Table 1). We calculated prevalence of individual impairment codes, and cumulative incidence of patients with any impaired mobility/function/disability using a competing risk model controlling for insurance disenrollment/end of study. We calculated 12-month cumulative incidence of presumptive SSDI (competing risk model), defined as patients <65 years old transitioning to Medicare (excluding those with ESRD and ALS, who automatically qualify), compared to US population statistics.³ This analysis is devoid of identifiable patient information and is exempt from IRB review requirements as per Ambros Therapeutics policy.

Results

189,483 patients met incident CRPS-1 criteria (female, 69%; mean age, 52±16 yrs; insurance: 47% commercial, 37% Medicare, 17% Medicaid). Of >36,000 ICD10 codes assigned in the 18 months after CRPS-1 diagnosis, 21 were associated with impaired mobility/function and disability; the most common indicating impaired walking and gait and need for continuous supervision (Table 1). The percentage of patients diagnosed with impairment/disability more than doubled (16.4% pre-diagnosis vs 37.0% at month 18; Figure 1). In the year after diagnosis, the percentage of patients with presumptive SSDI more than doubled from 1.3% to 3.2%, or 1126 to 3198 per 100,000 (Figure 2), which is meaningfully higher than the 185 per 100,000 US population norm.⁴ It should be noted that there is a significant lag from SSDI evaluation and application to approval, often >12 months. As such, most of the evaluations/applications would have happened in the year before initial CRPS-1 diagnosis, consistent with the known delay from symptom onset to CRPS-1 diagnosis⁴and before CRPS-1 was included as an MDI.

Discussion

This is the first large-scale, nationally representative study of mobility impairments/disability in CRPS-1. Within 18 months post-diagnosis, >1/3 patients had claims related to impaired mobility, including wheelchair requirement, bed confinement, and/or need for continuous supervision. Presumptive SSDI in the year post-diagnosis was elevated versus US population norms. These findings highlight the burden to patients and Medicare and the need for earlier diagnosis and approval of effective treatments for CRPS-1.

References

1. Johnson S, Cowell F, Gillespie S, Goebel A. Complex regional pain syndrome—what is the outcome? A systematic review of the course and impact of CRPS at 12 months from symptom onset and beyond. Eur J Pain. 2022;26(6):1203-1220.
2. Social Security Administration. DI 24580.025 - Evaluating Reflex Sympathetic Dystrophy/Complex Regional Pain Syndrome (RSDS/CRPS). https://secure.ssa.gov/apps10/poms.nsf/lnx/0424580025#b. Accessed July 31, 2025.
3. Social Security Administration. Disabled worker beneficiary statistics. https://www.ssa.gov/oact/STATS/dibStat.html. Accessed July 31, 2025.
4. Allen G, Galer BS, Schwartz L. Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain. 1999;80(3):539-544.

Poster

Background

• Complex regional pain syndrome type 1 (CRPS-1) is associated with significant impairments in functioning and health-related quality of life.
• CRPS-1 results from an injury without an identifiable nerve lesion, and associated pain and physical impairment can begin years before and persist years after diagnosis.¹
• Treatment options are limited with no FDA-approved pharmacologic treatments and current management focused on spinal cord and DRG stimulation, physical therapy and pain control.^2,3
• While CRPS-1 is not in the Social Security Administration Blue Book of impairments qualifying for disability, it was added as a Medically Determinable Impairment (MDI) in 2024.⁴

Objective

• Assess diagnoses of mobility/functional impairment and transition to presumptive Social Security Disability Insurance (SSDI) among patients after incident CRPS-1 diagnosis

Methods

• We conducted a retrospective cohort analysis using Komodo Health's primarily claims-derived Healthcare Map®, a longitudinal, nationally representative health service utilization database with >330 million de-identified, insured US-patients.
• Incident CRPS-1 patients (ICD10 G90.5x) diagnosed between 01/01/17
  and 12/31/24 were identified.
• Patients required to have ≥12 months of data with no CRPS-1 diagnosis and:
  • >1 inpatient and >1 outpatient claims with a CRPS-1 diagnosis; or
  • >2 outpatient claims with a CRPS-1 diagnosis >30 days apart; or
  • >2 inpatient stays each with a CRPS-1 diagnosis; or
  • An inpatient stay with a CRPS-1 diagnosis that lasted >7 days; or ended
    in death
• Patients were excluded if:
  • First CRPS-1 diagnosis appeared outside of their enrollment period;
  • Patients had ≥2 claims with a diagnosis of causalgia (i.e., CRPS-2, ICD10 G56.4x or G57.7x) in the year after initial CRPS-1 diagnosis; or
  • There were open claims
• The index date was defined as the first CRPS-1 diagnosis date in the observation period following the requisite 12 months without a diagnosis. Month 0 is before CRPS-1 diagnosis.
• Two reviewers adjudicated ICD10 codes in the 18 months after CRPS-1 diagnosis for those indicating impaired function/mobility/disability
  (Table 1).
• We calculated prevalence of individual impairment codes, and cumulative incidence of patients with any impaired mobility/function/disability using a competing risk model controlling for insurance disenrollment/end of study.
• We calculated 12-month cumulative incidence of presumptive SSDI (competing risk model), defined as patients <65 years old transitioning to Medicare (excluding those with ESRD and ALS, who automatically qualify)⁵, compared to US population statistics.⁶
• This analysis is devoid of identifiable patient information and is exempt
  from IRB review requirements.

Results

• 189,483 patients met incident CRPS-1 criteria (Figure 1)
• Patients were mostly female and in their early 50s (Table 1)
• Insurance: 47% commercial, 37% Medicare, 17% Medicaid
• Initial CRPS-1 Diagnosis: 47% upper limb, 23% lower limb
• Of >36,000 ICD10 codes assigned in the 18 months after CRPS-1 diagnosis
• 21 were associated with impaired mobility/function and disability
• The most common indicated impaired walking and gait and need for continuous supervision (Table 2)
• Patients with impairment/disability more than doubled over 18 months (16.4% pre-diagnosis vs 37.0% at month 18; Figure 2).
• In the year after diagnosis, the percentage of patients with presumptive SSDI more than doubled from 1.3% to 3.2%, or 1126 to 3198 per 100,000 (Figure 3).

Discussion

• This is the first large-scale, nationally representative study of mobility impairments/disability in patients with CRPS-1.
• Consistent with previous epidemiologic studies, CRPS-1 was most common in women >50 years
  of age.
• CRPS-1 was twice as common in lower versus upper limbs.
• Impaired function/mobility was dominated by problems with walking/gait and more than doubled in the year after diagnosis; a significant number of patients required continuous supervision.
• Presumptive SSDI in the 18-months post-diagnosis (1126 to 3198 per 100,000) was meaningfully higher than the 185 per 100,000 in the general US population.⁶
• Patients on SSDI make up a disproportionate share of Medicare costs: $21,954 per capita versus $15,992 Medicare overall, or 37% higher.⁵
• The strength of the data are that they characterize the medical treatments patients actually receive in the US.

Limitations

• Claims databases represent the insured US population, 92% during this time-period.
• Thesedata represent only patients diagnosed with CRPS-1.
• Though adjudicated, claims data can be incomplete and miscoding can happen.
• It should be noted that there is a significant lag from SSDI evaluation and application to approval, often >12 months. As such, most of the evaluations/applications would have happened in the year before initial CRPS-1 diagnosis, consistent with the known delay from symptom onset to CRPS-1 diagnosisand before CRPS-1 was included as an MDI

Key Takeaways

• Presumptive SSDI was meaningfully higher in CRPS-1 patients than in the general US population and is a known driver of Medicare cost.
• More than one-third of patients with CRPS-1 had claims related to impaired mobility, including need for continuous supervision.
• These findings highlight the burden to patients and disability insurers and the need for earlier diagnosis and approval of effective treatments for CRPS-1.

References

1. Schwartzman RJ, Erwin KL, Alexander GM. Clin J Pain 2009;25(4):273-280. 2. Abd-Elsayed A, Stark CW, Topoluk N, et al. Ann Med. 2024;56(1):2334398. Harden RN, McCabe CS, Goebel A, et al. Pain Med. 2022;23(Suppl 1):S1-S53. 4. Social Security Administration. DI 24580.025 - Evaluating Reflex Sympathetic Dystrophy/Complex Regional Pain Syndrome (RSDS/CRPS).  https://secure.ssa.gov/apps10/poms.nsf/lnx/0424580025. Accessed Oct 01, 2025. 5. Medicare Payment Advisory Commission. A Data Book: Health Care Spending and the Medicare Program. https://www.medpac.gov/wp-content/uploads/2025/07/July2025_MedPAC_DataBook_SEC.pdf. 6.Social Security Administration. Disabled worker beneficiary statistics. https://www.ssa.gov/oact/STATS/dibStat.html. Accessed Oct 01, 2025.