PROductivity Study of Presbyopia Elimination in Rural-dwellers II (PROSPERII)

Effects of Near Vision Spectacle Correction on Work Productivity Among Textile Factory Workers in India

The investigators will conduct a randomized-controlled trial. The participants will be textile workers aged 30 years and above with uncorrected presbyopia who are employed by a single Indian garment manufacturer - employed by Shahi Exports Private Limited, Karnataka, India - at facilities equipped to measure individual productivity. PROSPER II will assess the impact of free reading glasses on productivity for workers in a textile factory.

Study Overview

• Status: Recruiting
• Conditions: Presbyopia
• Intervention / Treatment: Device: Spectacles

Detailed Description

Globally, 3 billion people do not have the eyeglasses they need to earn, learn, travel safely in traffic and participate in civic life. Among these, 1.1 billion people lack a simple pair of reading glasses to correct impaired near vision, called presbyopia. Presbyopia, the essentially universal decline in unaided near vision that occurs with aging, is the world's most common cause of vision impairment. Loss of accommodation (ability to change focus from distance to near) due to 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.

Study Plan: This is a randomized trial designed to assess the impact of free spectacles on workplace productivity among Indian textile workers.

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

Design: Investigator-masked, multi-center randomized controlled trial

Rationale: Although presbyopia is safely, effectively and inexpensively treated with glasses, rates of optical correction in LMICs are as low as 10%. 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. 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). The largest reported effect sizes among such trials 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 (21.6%) compared to those in the control group. Costs were low, over half of pickers aged >= 40 years met criteria to receive glasses, and wearing compliance reached nearly 90%. There is interest to understand if these results from the agricultural setting can be extended to other financially-important sectors.

Methods : The investigators will enrol 800 textile workers aged 35 years and above with uncorrected presbyopia who are employed by Shahi Exports Private Limited in Karnataka, India. Eligible participants will be randomly assigned to Intervention and Control Groups (1:1). Intervention group participants will receive free reading glasses within a week of undergoing a vision screening at the factory. Control group participants will receive reading glasses at the end of the assessment period (three months after vision screening).

The main outcome 3 month later will be work productivity; secondary outcomes are change in skill grade, change in monthly wage, participants' adherence with spectacle wear, self-assessed self-efficacy score and change of quality of life scores. The intervention cost-effectiveness will be studied.

• Study Type: Interventional
• Enrollment (Estimated): 800
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Smit Gade; Phone Number: +7023679633; Email: gade@goodbusiness.com
• Study Contact Backup: Name: Nathan G Congdon, MD, MPH; Phone Number: 07748751393; Email: ncongdon1@gmail.com

Study Locations

• India
  • Karnataka
    • Bengaluru, Karnataka, India, 560102
      • Recruiting
      • Good Business Lab
      • Contact: Simranjeet Dhir; Email: simranjeet.d@goodbusinesslab.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 35 years and older
• Have presbyopia, defined as an unaided near visual acuity of N6.3 or worse in both eyes
• Require a new pair of glasses to improve their near vision
• Have a corrected near visual acuity of N4 or better in both eyes
• Have worked in Shahi's production department as tailors or Kajbutton operators for 6 weeks or more

Exclusion Criteria:

• Have ocular pathology in either eye detected during the eye examination, or history of such disease based on self-report
• Have a 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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 (September 2021). The assessment period will be three months; Other Names: Near eyeglasses; Reading glasses
No Intervention: Control; Workers assigned to the Control group will receive similar free glasses at the end of the study assessment (3 months).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in change in mean efficiency between intervention and control group	Efficiency is calculated as the proportion of target production realized by a worker per unit time	Over the three month follow-up period from enrolment to study completion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Three-month change in skill grade	Skill grade ranges from A triple star (highest) to A double star, A star, A, B, and C + (lowest)	Between baseline and study end three months later
Change in monthly wage	Monthly wage (Factory administrative data)	Between baseline and study end three months later
Adherence with spectacle wear	measured weekly by enumerator's unannounced observations of the presence of spectacles worn on the participant's face.	Between baseline and study end three months later
Group difference in three-month change in self-assessed self-efficacy scores	Self-assessed self-efficacy scores measured using the Cantril's Ladder, with the best possible score being a 10, and the worst being a 0 (Cantril's Ladder)	Between baseline and conclusion of the study three months later
Group difference in three-month change of quality of life scores	Quality of life scores measured using the APEDS Visual Function Questionnaire (VFQ)	Between baseline and conclusion of the study three months later
Cost effectiveness	Full programme costs per individual identified and corrected with presbyopia. Programme costs include costs incurred in screening test, glasses / replacement and direct/indirect costs for facilitating work-based site. Benefit will be measured using work productivity. We will report cost effectiveness distinguishing between study costs and program costs	Between baseline and study end three months later

Collaborators and Investigators

• Sponsor: Queen's University, Belfast
• Collaborators: University of Michigan; Zhongshan Ophthalmic Center, Sun Yat-sen University; VisionSpring; Good Business Lab; Clearly
• Investigators: Principal Investigator: Nathan G Congdon, MD, MPH, Queen's University, Belfast

Study record dates

Study Major Dates

• Study Start (Actual): August 3, 2023
• Primary Completion (Estimated): June 30, 2024
• Study Completion (Estimated): June 30, 2024

Study Registration Dates

• First Submitted: October 21, 2020
• First Submitted That Met QC Criteria: November 10, 2020
• First Posted (Actual): November 16, 2020

Study Record Updates

• Last Update Posted (Estimated): December 7, 2023
• Last Update Submitted That Met QC Criteria: November 30, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Presbyopia; Refractive error; Work productivity; Spectacle wear compliance
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Presbyopia
• Other Study ID Numbers: MHLS 20_82

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified data will be made available for download on the Queen's University Belfast website.
• IPD Sharing Time Frame: Within 6 months of collection, for three years.
• IPD Sharing Access Criteria: Freely available
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No