Prescription opioid abuse is associated with substantial
economic burden, with estimates of incremental annual per-patient health care
costs of diagnosed opioid abuse exceeding $10,000 in prior literature. A subset
of patients diagnosed with opioid abuse has disproportionately high health care
costs, but little is known about the characteristics of these patients.
To describe the characteristics of a subset of patients
diagnosed with opioid abuse with disproportionately high health care costs to
assist physicians and managed care organizations in targeting interventions at
the costliest patients.
This retrospective claims data analysis identified patients
aged 12 to 64 years diagnosed with opioid abuse/dependence in the OptumHealth
Reporting and Insights medical and pharmacy claims database, Quarter 1 (Q1)
1999-Q1 2012. Inclusion criteria required that patients had a diagnosis of
opioid abuse during or after Q1 2006, no prior diagnoses of opioid abuse, and
continuous non-HMO coverage over an 18-month study period. The study period
comprised a 12-month observation period centered on the date of the first
opioid abuse diagnosis (index date) and a 6-month baseline period immediately
preceding the observation period. Patients in the top 20% of total health care
costs in the observation period were classified as "high-cost
patients," and the remaining patients were classified as "lower-cost
patients." Patient characteristics, comorbidities, health care resource
use, and health care costs were compared between high-cost patients and
lower-cost patients using chi-square tests for dichotomous variables and
Wilcoxon rank-sum tests for continuous variables. In addition, multivariate
regression was used to assess the relationship between patient characteristics
in the baseline period and total health care costs in the observation period
among all patients diagnosed with opioid abuse.
9,291 patients diagnosed with opioid abuse met the inclusion
criteria.
- The 20% of patients classified as high-cost patients accounted for approximately
two thirds of the total health care costs of patients diagnosed with opioid
abuse.
- Compared with lower-cost patients, high-cost patients were older (42.5
vs. 36.1) and more likely to be female (55.9% vs. 42.9%).
- They had a higher comorbidity burden at baseline, as
reflected in the Charlson Comorbidity Index (0.8 vs. 0.2),
- and rates of conditions such as chronic pulmonary disease (12.9% vs. 5.6% and mild/moderate diabetes (8.4% vs. 3.4%).
- High-cost patients also had
- higher rates of nonopioid substance abuse
diagnoses (12.4% vs. 8.9%)
- and psychotic disorders (26.5%
vs. 13.6%).
- In the observation period, high-cost patients
continued to have
- higher rates of nonopioid substance abuse diagnoses (53.0%
vs. 47.2%)
- and psychotic disorders (67.1% vs. 47.5%).
- In addition, they had greater medical resource use across all
places of service (i.e., inpatient, emergency department, outpatient,
drug/alcohol rehabilitation facility, and other) compared with lower-cost
patients.
- The mean observation period health care costs of high-cost patients
was $89,177 compared with $11,653 for lower-cost patients.
- High-cost patients had higher medical costs linked to claims with an
opioid abuse diagnosis in absolute terms, but the share of total medical costs
attributed to such claims was lower among high-cost patients than among
lower-cost patients.
- While many baseline characteristics were found to have a
statistically significant (P less than 0.05) association with observation
period health care costs, only 27.3% of the variation in observation period
health care costs was explained by patient characteristics in the baseline
period.
This study found that the costliest patients diagnosed with
opioid abuse had high rates of preexisting and concurrent chronic comorbidities
and mental health conditions, suggesting potential indicators for targeted
intervention and a need for greater awareness and screening of comorbid
conditions.
Opioid abuse may exacerbate existing conditions and make it
difficult for patients to adhere to treatment plans for those underlying
conditions. Baseline patient characteristics explained only a small share of the
variation in observation period health care costs, however.
Future research
should explore the degree to which other factors not captured in administrative
claims data (e.g., severity of abuse) can explain the wide variation in health
care costs among opioid abusers.
1Analysis Group, 111 Huntington Ave., Tenth Fl., Boston, MA 02199.
