Study on Incentives for Glaucoma Medications Adherence (SIGMA)

April 28, 2017 updated by: Marcel Bilger, Duke-NUS Graduate Medical School

A Randomized Controlled Trial to Increase Glaucoma Medication Adherence Using Value Pricing

Glaucoma topical eye medications, when adhered to, are effective at controlling disease progression. Yet evidence shows that many glaucoma patients have incomplete adherence to medications, with disease progression resulting in significant costs to the patient and health system. Through the approach of value pricing, a link can be made between non-adherence and its resulting costs by granting subsidies to adherent patients for their medications and physician visits. This 6-month randomized controlled trial among 100 glaucoma patients from the Singapore National Eye Centre aims to test the extent to which value pricing can improve medication adherence.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

By reducing intraocular pressure, glaucoma topical eye medications are effective at controlling disease progression for the majority of patients. Yet evidence shows that many glaucoma patients have incomplete adherence to medications, resulting in significant personal costs in terms of disease progression and visual field loss. The cost to the health system from poor adherence is also substantial as glaucoma surgery is more costly than treatment with topical medication. Behavioural economics theory suggests that adherence rates can be improved by providing a clearer link between non-adherence and the resulting costs thereof. In the proposed study, this link is made by granting subsidies to adherent patients for their medications and physician visits, whereas those who are not sufficiently adherent would not receive the subsidy and thus pay a higher rate for their treatment.

These subsidies provide a financial incentive for patients to take their medicines as prescribed, and because prescription refills and visits occur regularly, also provide a tangible and near-term cost resulting from non-adherence. The investigators refer to this approach as value pricing as subsidies are allocated to medications that have not only been shown to be clinically effective but that are also effectively used by the patient. In efforts to increase adherence among glaucoma patients in Singapore, the investigators propose to conduct a 6-month proof-of-concept randomized controlled trial among 100 participants from the Singapore National Eye Centre (SNEC) to test the extent to which value pricing can improve medication adherence. As Singapore's population continues to age and a larger share of the population requires daily medications to treat chronic diseases, such innovative solutions are needed to ensure not only that patients take their medications as prescribed and receive the full benefit of their treatment but also that Government subsidies are allocated effectively so that to ensure the sustainability of the health system.

Specific Aim and hypothesis tested:

Aim: Test whether adding Value Pricing (VP) to Usual Care (UC) can improve medication adherence over a 6-month period.

Hypothesis: VP patients will show greater adherence rates at 6 months compared to those receiving only UC.

Study Type

Interventional

Enrollment (Actual)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Singapore
      • Singapore, Singapore
        • Singapore National Eye Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Singaporean citizens or permanent residents
  • Conversant in English or Mandarin
  • Taking at least one glaucoma eye drop medication
  • Shown to be non-adherent based on a value of 6 or less on the Modified Medication Adherence Scale (MMAS)

Exclusion Criteria:

  • Significant comorbid conditions preventing application of medications without assistance
  • Stage 4 (advanced) or Stage 5 (end stage) glaucoma according to the Glaucoma Staging System

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Usual Care (UC)

Patients receiving Usual Care for Glaucoma comprising:

  • Education on effective glaucoma treatment
  • Routine check-ups with an ophthalmologist and prescription of glaucoma eye drops

  • Glaucoma counselling [Can be recommended by ophthalmologist for non-adherent patients] covering:

    • Glaucoma risk factors and symptoms
    • Management and treatment
    • Medications and optimal dosage windows
    • Risks of medication non-adherence
    • Formulation of a dosing schedule that compliments each patient's lifestyle
Experimental: Value Pricing (VP)
Patient receiving Usual Care for Glaucoma and given the opportunity to receive Value Pricing Subsidies.
Behavioral: Value Pricing Subsidies
  • Usual care for glaucoma
  • Subsidies granted to adherent patients for their glaucoma medications and physician visits, lowering the costs of treatment and providing a financial incentive for patients to take their medicines as prescribed.
  • Subsidy (25 / 50%) granted based on meeting dose-rate adherence percentage targets (75 / 90%) at the month 3 and 6 assessment points.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Monthly dose-rate adherence percentage
Time Frame: Month 6
The proportion of days across a month where a patient took all medication(s) within the appropriate dosing windows (morning, afternoon, evening) for the day.
Month 6

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Dose-rate adherence percentage
Time Frame: Months 1 - 6
The proportion of days across the study period where a patient took all medication(s) within the appropriate dosing windows (morning, afternoon, evening) for the day.
Months 1 - 6
Proportion meeting 90% dose-rate adherence percentage
Time Frame: Months 3 & 6
The proportion of participants at each time point who met the 90% dose-rate adherence percentage cut-off for each monitoring period.
Months 3 & 6
Proportion meeting 75% dose-rate adherence percentage
Time Frame: Months 3 & 6
The percentage of participants at each time point who met the 75% dose-rate adherence percentage cut-off for each monitoring period.
Months 3 & 6
Intraocular Pressure
Time Frame: Baseline & Month 6
Intraocular Pressure measured using established protocols at SNEC.
Baseline & Month 6
EQ-5D-5L
Time Frame: Baseline & Month 6
Scale to assess health related quality of life.
Baseline & Month 6
Glaucoma Quality of Life (GQL-15)
Time Frame: Baseline & Month 6
Scale to measure quality of life, pertaining specifically to aspects of QoL that can be affected by the glaucoma condition.
Baseline & Month 6

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Duke-NUS Graduate Medical School

Collaborators

Singapore National Eye Centre

Investigators

  • Principal Investigator: Marcel Bilger, PhD, Duke-NUS Graduate Medical School

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2014

Primary Completion (Actual)

January 1, 2017

Study Completion (Actual)

February 1, 2017

Study Registration Dates

First Submitted

October 19, 2014

First Submitted That Met QC Criteria

October 21, 2014

First Posted (Estimate)

October 22, 2014

Study Record Updates

Last Update Posted (Actual)

May 1, 2017

Last Update Submitted That Met QC Criteria

April 28, 2017

Last Verified

April 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HSRNIG12nov007

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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