Benefits of Adherence to 5-alpha Reductase Inhibitor Treatment in Men With Enlarged Prostate: An Assessment of Medicare and Medicaid Patients Using the MarketScan Database

Adherence and length of treatment with a 5-alpha reductase inhibitor (5ARI) therapy may be associated with improved clinical outcomes for patients with enlarged prostates (EP) and lower health care related costs.

The objectives of this study are to quantify 1.) the relationship between 5ARI adherence and length of therapy and the likelihood of acute urinary retention (AUR), prostate-related surgery (emergency and non-emergency), and clinical progression (defined as AUR and/or prostate-related surgery); and 2.) the monthly EP-related, medical costs in a Medicaid and Medicare population. The null hypothesis is that no differences will be observed in the outcomes and costs of patients who adhere to long-term 5ARI therapy and those who do not. The test hypothesis is that patients with higher levels of adherence to 5ARI for a longer period of time will experience significantly fewer adverse outcomes and significantly lower treatment costs.

The data source for this analysis is the MarketScan database, which contains medical and pharmacy claims for commercial health plan members and Medicare recipients. Medical and pharmacy claims data are sourced directly from health plans and employers. The database represents approximately 18 to 20 million individuals annually and nearly 22 million Medicaid enrollees from multiple states. The database includes the Medicare-covered portion of payment, the employer-paid portion, and any out-of-pocket expenses paid by the beneficiary.

The study design is a retrospective cohort analysis. Each patient's index date was defined as the date of the first fill for a 5ARI prescription.

Study Overview

• Status: Completed
• Conditions: Prostatic Hyperplasia
• Intervention / Treatment: Drug: 5ARI

• Study Type: Observational
• Enrollment (Actual): 28903

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

The study will include retrospective data from male patients aged 65 years and older with continuous health plan enrollment from July 1, 2003 and June 30, 2009. Patient records will be reviewed for data from the 6-months prior to and 1-year following the index date, which represents the first prescription fill for a 5ARI

Description

Inclusion Criteria:

• Male
• Age 65 or older
• A diagnostic claim of BPH (ICD-9-CM code 222.2x or 600.xx)
• A prescription claim for a 5ARI for at least 60 days during the observation period
• Continuous eligibility for 6 months prior to and at least 91 days after the index date

Exclusion Criteria:

• A prostate cancer diagnosis
• A procedure cost for any prostate-related surgical procedure prior to the index date

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients adherent to 5-alpha reductase inhibitor (5ARI); Patients with benign prostate hyperplasia (BPH) who are adherent (as measured by a medication possession ratio (MPR)) based on 3 MPR threshold values of 70%, 75% and 80%	Drug: 5ARI; dutasteride or finasteride; Other Names: Proscar® (finasteride); Avodart® (dutasteride)
Patients who are non-adherent to 5ARI therapy; Patients with BPH who are not adherent to 5ARI therapy as measured by 3 MPR threshold values of 70%, 75%, and 80%	Drug: 5ARI; dutasteride or finasteride; Other Names: Proscar® (finasteride); Avodart® (dutasteride)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean number of patients with a diagnosis code for acute urinary retention (AUR) and/or a procedure code for prostate surgery	AUR and prostate surgery are indicative of clinical progression of enlarged prostate (EP)	1 year following the first therapy date or until an event that signifies clinical progression is observed (whichever occurs first)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adjusted benign prostatic hyperplasia (BPH)-related costs	Differences in cost will be compared across cohorts. BPH-related costs include those associated with ICD-9-CM codes 222.2x or 600.xx	1 year following the first therapy date
Medication Possession Ratio (MPR)	A measure of medication adherence (compliance and discontinuation) in patients taking monotherapy versus early combination therapy. Discontinuation is defined as a 30-day gap in therapy	1 year following the first therapy date

Collaborators and Investigators

• Sponsor: GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start: October 1, 2010
• Primary Completion (Actual): December 1, 2010
• Study Completion (Actual): December 1, 2010

Study Registration Dates

• First Submitted: June 16, 2011
• First Submitted That Met QC Criteria: June 16, 2011
• First Posted (Estimate): June 20, 2011

Study Record Updates

• Last Update Posted (Actual): May 22, 2017
• Last Update Submitted That Met QC Criteria: May 19, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Keywords: adherence; surgery; benign prostatic hyperplasia; 5-alpha reductase inhibitor; enlarged prostate; acute urinary retention
• Additional Relevant MeSH Terms: Pathologic Processes; Prostatic Diseases; Prostatic Hyperplasia; Hyperplasia; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Urological Agents; Enzyme Inhibitors; Hormones, Hormone Substitutes, and Hormone Antagonists; Hormone Antagonists; Steroid Synthesis Inhibitors; 5-alpha Reductase Inhibitors; Dutasteride; Finasteride
• Other Study ID Numbers: 113907