Cost and consequences of noncompliance with osteoporosis treatment among women initiating therapy

Abstract

Objective:

The objective was to evaluate compliance with osteoporosis (OP) treatments and determine the fracture and healthcare burden associated with noncompliance.

Methods:

This retrospective analysis of a US claims database identified women initiating an OP medication from 1 January 2002 to 30 June 2009. Patients were ≥55 years and had ≥1 pharmacy claim for a bisphosphonate or non-bisphosphonate (raloxifene, calcitonin, teriparatide); the index date was the first pharmacy claim. There were three study periods: baseline (12 months pre-index); compliance period (0–12 months post-index); and follow-up period (12–24 months post-index). Medication possession ratio (MPR) was calculated during the compliance period to differentiate two cohorts: compliant (MPR ≥ 80%) and noncompliant (MPR < 80%). Outcomes during follow-up were modeled by logistic regression (presence of fracture), Poisson regression (healthcare utilization incidence rate) and gamma regression (healthcare costs), all adjusted for patient demographic and clinical characteristics.

Results:

Overall, 685,505 women initiating OP therapy were identified and 57,913 (8.4%) met the inclusion criteria: only 23,430 (40.5%) were compliant and 34,483 (59.5%) were noncompliant. Mean age was 64 years. Noncompliance was associated with a 20% higher risk of any fracture (odds ratio: 1.20, 95% CI = 1.07–1.35), a higher incidence rate ratio (IRR) for inpatient utilization (IRR: 1.26, 95% CI = 1.19–1.34) and a lower rate of outpatient utilization (IRR: 0.97, 95% CI = 0.95–0.98). Noncompliant patients had 13% higher medical costs (cost ratio: 1.13, 95% CI = 1.06–1.21) than compliant patients.

Limitations:

Inclusion in this study required 36 months of continuous healthcare coverage. Thus, the results are primarily applicable to a stable, managed care population and may not be generalizable to other populations.

Conclusion:

Noncompliance with OP therapy was associated with a higher risk of fracture, higher all-cause medical costs and a higher frequency of inpatient service utilization. Additional research is needed to identify barriers to compliance with OP therapy.

Keywords: :

• Adherence
• Compliance
• Fracture risk
• Healthcare costs
• Healthcare utilization
• Osteoporosis

Transparency

Declaration of funding

This study was sponsored by Merck & Company Inc., Lebanon, NJ, USA.

Declaration of financial/other relationships

A.M. and S.S. have disclosed that they are employees of Merck Sharp & Dohme Corp., and hold stock in the company. J.T. has disclosed that he is an employee of Asclepius Analytics Ltd, a company supported by Merck to develop this study. E.S.S. has disclosed that she is a consultant to Merck, Amgen, Lilly, and Radius.

CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work. Peer reviewer 1 has disclosed that she has received research grants from Amgen. Peer reviewer 2 has disclosed that she is a consultant to Amgen, Abbott, and Medimmune.

Acknowledgment

Sarah Peirce-Sandner MS (Optum, Eden Prairie, MN, USA) provided medical writing support for this manuscript that was funded by Merck & Company.

Previous presentation: A portion of this work was presented as a poster at the Academy of Managed Care Pharmacy 2013 NEXUS conference, San Antonio, TX, USA, 15–18 October 2013.