PROductivity Study of Presbyopia Elimination in Rural-dwellers III (PROSPERIII)

April 25, 2024 updated by: Nathan Congdon, Queen's University, Belfast

Effects of Near Vision Spectacle Correction on Work Retention Among Textile Factories Workers in India

The investigators will conduct an embedded mixed methods study in which the primary approach is a randomized controlled trial (RCT), and the secondary or embedded approach is a descriptive qualitative study. The aim of the RCT is to assess the impact of presbyopic correction on workplace productivity and retention in the textile industry in a low middle-income country. Additional qualitative data will be collected to enhance understanding of factors linked to reasons why enrolled sew-ers left their job during the study. Participants will be textile workers aged 30 years and above with uncorrected presbyopia who are employed by Shahi Exports Private Limited in Karnataka, India.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Globally, 1.1 billion people lack a simple pair of reading glasses to correct impaired near vision, called presbyopia. Presbyopia can begin as early as age 30 years, commonly becomes functionally apparent by 40, and is essentially complete by 55 meaning that presbyopia is most common at the height of the working years. The global productivity loss due to uncorrected presbyopia has been estimated to exceed US$25 billion, and presbyopia is shown to be associated with significant impairment in activities of daily living. There is paucity in trial evidence of the impact on near vision spectacle correction on work productivity and workplace retention. The largest reported effect sizes among such trials (specifically for productivity) was the PROSPER trial, which showed that providing inexpensive near vision glasses increased the daily weight of tea picked among presbyopic, mostly-female Indian agricultural workers by more than 5 kg (21.7%) compared to those in the control group.

Study Plan: The investigators will choose 1260 textile workers aged 30 years and above with uncorrected presbyopia who are employed by Shahi Exports Private Limited in Karnataka, India. They will be randomly assigned into one of two groups: a group receiving free reading glasses within one week of undergoing vision assessment ("Intervention") or a group receiving identical reading glasses at the end of the assessment period ("Control").The main study outcome will be the proportion of workers who continue working at the factories in the intervention group (as opposed to control). The investigators anticipate that the glasses intervention will increase retention by 20% in the Intervention group at 1 year.

The study will also assess the workers' efficiency, why they have left employment, how satisfied and valued they felt at their work and how often they use their glasses for work. These other outcomes will help the investigators to better understand the causal pathway between vision and work retention. The investigators will also study the total cost of providing glasses per additional worker retain their employment.

Research question: Will providing free glasses to presbyopic Indian textile workers increase work retention?

Design: Investigator-masked, multi-center randomized controlled trial with a qualitative component

Rationale: Although presbyopia is safely, effectively and inexpensively treated with glasses, rates of optical correction in LMICs are as low as 10%. The way in which firms manage workers has profound implications for performance by way of worker attendance, retention, and productivity. Similarly, worker engagement, and the extent to which workers feel valued, is a key determinant of firm performance. As the low-skill workforce in many developing countries transitions rapidly from agriculture to industrial work, employers struggle with high worker turnover due to poor working conditions, low pay, and restricted worker rights. Few trials have been published which address the question of whether healthcare interventions can improve work performance as well as workplace retention, especially among persons over the age of 40 in low and middle-income countries (LMICs). There is interest in understanding if these results obtained in an agricultural setting can be extended to other financially-important sectors.

Methods: The investigators will choose 1260 textile workers aged 30 years and above with uncorrected presbyopia who are employed by Shahi Exports Private Limited in Karnataka, India. They will be randomly assigned into one of two groups: a group receiving free reading glasses within one week of undergoing vision assessment ("Intervention") or a group receiving identical reading glasses at the end of the assessment period ("Control").

The main outcome 18 month later will be work retention; secondary outcomes are workers' efficiency, the reasons the workers left their employment, satisfaction and perceived self-valued at work and glasses wear adherence at work. Attitudes about presbyopia and spectacle use and intervention cost-effectiveness will be studied.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
1291

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

  • India
    • Karantaka
      • Bengaluru, Karantaka, India, 560102
        • Good Business Lab

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

30 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 30 years and above
  • Distance visual acuity >= 6/12 in both eyes
  • Presence of presbyopia, defined as the inability, correctable with reading glasses, to read the N8 line using both eyes together, on a tumbling near vision chart at a distance of 25cm, 30cm, 40cm, and 50cm based on workers working distance
  • Employed at the factory for >=3months in the sewing department

Exclusion Criteria:

  • Current ownership of reading or distance glasses (regardless of accuracy)
  • Obvious evidence of ocular disease in either eye detected during the eye examination, or history of such disease based on self-report
  • Low likelihood of completing follow-up in the study due to current plans to move out of the area or leave employment at Shahi during the follow-up period

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Intervention
Workers assigned to the intervention group will receive free spectacles of a design they select, based on the worker's measured refractive power and dispensed one week later at the factory by the study ophthalmic personnel.
Device: Spectacles
Intervention group workers receive free glasses within one week of undergoing vision assessment (May 2022). The duration of the treatment for the Intervention participants will depend on when they leave employment at the factor. If they stayed for the full duration of the trial, they will have undergone a maximum of 18 months (December 2023).
Other Names:
  • Eyeglasses
  • Reading glasses
No Intervention: Control
Workers assigned to the Control group will receive similar free glasses at the end of the study assessment (18 months).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Work retention
Time Frame: September 2022 to May 2024; Over the 18 month follow-up period from enrolment to study completion
Proportion of textile workers who continue to work at the textile factories assessed from trial entry to closure as recorded in Shahi's Human Resource Management Database
September 2022 to May 2024; Over the 18 month follow-up period from enrolment to study completion

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Compliance with spectacle wear
Time Frame: 3, 6, 9, 12, 15 and 18 months after enrolment
Actual presence of spectacles on the worker's face at work as reported by supervisor at the time of unannounced observation
3, 6, 9, 12, 15 and 18 months after enrolment
Change in work satisfaction
Time Frame: Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Proportion of sew-ers who state they are satisfied or very satisfied with work, feel valued or very valued at work, and are likely or very likely to stay with Shahi
Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Change in feeling valued-at-work
Time Frame: Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Proportion of sew-ers who state they feel valued or very valued working at Shahi
Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Change in likeliness to stay at work
Time Frame: Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Proportion of sew-ers who state they are likely or very likely to stay with Shahi
Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Change in work efficiency
Time Frame: Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Self-assessed productivity scores using the Cantril's Ladder, with the best possible score being a 10, and the worst being a 0.
Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Attitudes towards vision correction
Time Frame: At month 0
Worker's self-reported attitudes towards vision correction
At month 0
Access to local eyecare services
Time Frame: At month 0
Worker's self-reported access to local eyecare services
At month 0
History of uptake of eyecare services
Time Frame: At month 0
Worker's self-reported history of uptake of eyecare services
At month 0
Change in Quality of Life as assessed by the THRIVE Near Vision Quality of Life tool
Time Frame: Between baseline and endline at 18 months
Self-reported quality of life scores measured with the modified THRIVE Near Vision Quality of Life tool, a Likert Scale ranging from 1 (least affected) to 5 (worst affected).
Between baseline and endline at 18 months
Reasons leaving employment at Shahi
Time Frame: 2 months within participants leaving employment
Reasons given by the former supervisor and colleagues of former sew-ers for workers no longer being employed at Shahi
2 months within participants leaving employment
Change in work productivity
Time Frame: Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Proportion of target production realized by a worker per unit time.
Between baseline and 3, 6, 9, 12, 15 and 18 months after enrolment
Cost effectiveness of intervention
Time Frame: At study closeout at 18 months
Ratio of incremental program cost to additional workers in the intervention group who retain employment vs. those in the control group. Incremental cost is the difference of program costs between implementation of intervention and control (not including study costs, such as data collection).
At study closeout at 18 months
Change in skill grade
Time Frame: Between baseline and endline at 18 months
Worker's skill grade as reported by supervisor.
Between baseline and endline at 18 months
Change in monthly wage
Time Frame: Between baseline and endline at 18 months
Worker's monthly wage as reported by supervisor.
Between baseline and endline at 18 months

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Queen's University, Belfast

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Michigan
Zhongshan Ophthalmic Center, Sun Yat-sen University
VisionSpring
Good Business Lab
Clearly

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Nathan G Congdon, MD, MPH, Queen's University, Belfast

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 21, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 30, 2023

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 5, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 21, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 1, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 4, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 29, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 25, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • MHLS 20_84

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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