Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial
Summary: Background: Presbyopia, age-related decline in near vision, is the most common cause of vision impairment globally, but no trials have assessed its workplace effects. We aimed to study the effect of near glasses on the productivity of tea workers with presbyopia. Methods: This randomised t...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2018-09-01
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| Series: | The Lancet Global Health |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214109X18303292 |
| _version_ | 1819101263405514752 |
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| author | Priya Adhisesha Reddy, MBA Nathan Congdon, ProfMD Graeme MacKenzie, DPhil Parikshit Gogate, FRCS (Edin) Qing Wen, PhD Catherine Jan, BOptom (Hon) Mike Clarke, ProfDPhil Jordan Kassalow, OD Ella Gudwin, MA Ciaran O'Neill, ProfPhD Ling Jin, MS Jianjun Tang, PhD Ken Bassett, ProfMD David H Cherwek, MD Rahul Ali, MBBS |
| author_facet | Priya Adhisesha Reddy, MBA Nathan Congdon, ProfMD Graeme MacKenzie, DPhil Parikshit Gogate, FRCS (Edin) Qing Wen, PhD Catherine Jan, BOptom (Hon) Mike Clarke, ProfDPhil Jordan Kassalow, OD Ella Gudwin, MA Ciaran O'Neill, ProfPhD Ling Jin, MS Jianjun Tang, PhD Ken Bassett, ProfMD David H Cherwek, MD Rahul Ali, MBBS |
| author_sort | Priya Adhisesha Reddy, MBA |
| collection | DOAJ |
| description | Summary: Background: Presbyopia, age-related decline in near vision, is the most common cause of vision impairment globally, but no trials have assessed its workplace effects. We aimed to study the effect of near glasses on the productivity of tea workers with presbyopia. Methods: This randomised trial was done in tea pickers aged 40 years or older in Assam, India, with unaided near visual acuity (NVA) lower than 6/12 in both eyes, correctable to 6/7·5 with near glasses; unaided distance vision 6/7·5 or greater; and no eye disease. Participants were randomly assigned (1:1) to receive free glasses optimising NVA at working distance (cost including delivery US$10·20 per person), either immediately (intervention group) or at closeout (control group). Participants were stratified by age, sex, and productivity. The primary outcome (investigator-masked) was the difference between groups in the change in mean daily weight of tea picked (productivity), between the 4-week baseline period (June, 2017) and the 11-week evaluation period (July 24, 2017, to Oct 7, 2017). Workers' income was tied to their productivity. Compliance with study glasses was assessed at seven unannounced visits. Results were analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT03228199. Findings: Between July 3, 2017, and July 15, 2017, 1297 (48·1%) of 2699 permanent workers met the age criteria and consented for eye examinations. 751 (57·9%) fulfilled vision criteria and were randomly assigned to the intervention (n=376) or control (n=375) groups. Groups did not differ substantially in baseline characteristics. No participants owned glasses at baseline, 707 (94·1%) received the allocated intervention, and all were followed up and analysed. Between the baseline and evaluation periods, mean productivity in the intervention group increased from 25·0 kg per day to 34·8 kg per day (an increase of 9·84 kg per day), a significantly higher increase than in the control group (from 26·0 kg per day to 30·6 kg per day; an increase of 4·59 kg per day), corresponding to a between-group difference of 5·25 kg per day (95% CI 4·50–5·99; 21·7% relative productivity increase; effect size 1·01 [95% CI 0·86–1·16]; p<0·0001). Intervention-group compliance with study glasses reached 84·5% by closeout. Regression model predictors of greater productivity increase included intervention group membership (5·25 kg per day [95% CI 4·60–5·91], p<0·0001) and, among intervention participants, older age (p=0·039) and better compliance with the intervention (p<0·0001). Interpretation: A substantial productivity increase was achieved in this rural cohort by providing glasses to correct presbyopia, with little cost and high intervention uptake. Funding: Clearly. |
| first_indexed | 2024-12-22T01:15:53Z |
| format | Article |
| id | doaj.art-7668ad00eb0d4d039bd08cc60fa59c8e |
| institution | Directory Open Access Journal |
| issn | 2214-109X |
| language | English |
| last_indexed | 2024-12-22T01:15:53Z |
| publishDate | 2018-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | The Lancet Global Health |
| spelling | doaj.art-7668ad00eb0d4d039bd08cc60fa59c8e2022-12-21T18:43:52ZengElsevierThe Lancet Global Health2214-109X2018-09-0169e1019e1027Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trialPriya Adhisesha Reddy, MBA0Nathan Congdon, ProfMD1Graeme MacKenzie, DPhil2Parikshit Gogate, FRCS (Edin)3Qing Wen, PhD4Catherine Jan, BOptom (Hon)5Mike Clarke, ProfDPhil6Jordan Kassalow, OD7Ella Gudwin, MA8Ciaran O'Neill, ProfPhD9Ling Jin, MS10Jianjun Tang, PhD11Ken Bassett, ProfMD12David H Cherwek, MD13Rahul Ali, MBBS14Aravind Eye Hospital and Post-graduate Institute of Ophthalmology, Pondicherry, IndiaQueen's University Belfast, Belfast, UK; Orbis International, New York, NY, USA; State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; Correspondence to: Prof Nathan Congdon, Queen's University Belfast, Centre for Public Health, Royal Victoria Hospital, Belfast BT12 6AB, UK; State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangzhou, People's Republic of ChinaRiemann Limited, London, UKCommunity Eye Care Foundation, Pune, India; Padmashri D Y Patil Medical College, Pimpri, Pune, India; Lions NAB Eye Hospital, Miraj, IndiaQueen's University Belfast, Belfast, UKSchool of Psychological and Cognitive Sciences, Peking University, Beijing, ChinaQueen's University Belfast, Belfast, UKVisionSpring, New York, NY, USAVisionSpring, New York, NY, USAQueen's University Belfast, Belfast, UKState Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, ChinaQueen's University Belfast, Belfast, UKUniversity of British Columbia, Vancouver, BC, Canada; Seva Canada, Vancouver, BC, CanadaOrbis International, New York, NY, USAOrbis International, New York, NY, USASummary: Background: Presbyopia, age-related decline in near vision, is the most common cause of vision impairment globally, but no trials have assessed its workplace effects. We aimed to study the effect of near glasses on the productivity of tea workers with presbyopia. Methods: This randomised trial was done in tea pickers aged 40 years or older in Assam, India, with unaided near visual acuity (NVA) lower than 6/12 in both eyes, correctable to 6/7·5 with near glasses; unaided distance vision 6/7·5 or greater; and no eye disease. Participants were randomly assigned (1:1) to receive free glasses optimising NVA at working distance (cost including delivery US$10·20 per person), either immediately (intervention group) or at closeout (control group). Participants were stratified by age, sex, and productivity. The primary outcome (investigator-masked) was the difference between groups in the change in mean daily weight of tea picked (productivity), between the 4-week baseline period (June, 2017) and the 11-week evaluation period (July 24, 2017, to Oct 7, 2017). Workers' income was tied to their productivity. Compliance with study glasses was assessed at seven unannounced visits. Results were analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT03228199. Findings: Between July 3, 2017, and July 15, 2017, 1297 (48·1%) of 2699 permanent workers met the age criteria and consented for eye examinations. 751 (57·9%) fulfilled vision criteria and were randomly assigned to the intervention (n=376) or control (n=375) groups. Groups did not differ substantially in baseline characteristics. No participants owned glasses at baseline, 707 (94·1%) received the allocated intervention, and all were followed up and analysed. Between the baseline and evaluation periods, mean productivity in the intervention group increased from 25·0 kg per day to 34·8 kg per day (an increase of 9·84 kg per day), a significantly higher increase than in the control group (from 26·0 kg per day to 30·6 kg per day; an increase of 4·59 kg per day), corresponding to a between-group difference of 5·25 kg per day (95% CI 4·50–5·99; 21·7% relative productivity increase; effect size 1·01 [95% CI 0·86–1·16]; p<0·0001). Intervention-group compliance with study glasses reached 84·5% by closeout. Regression model predictors of greater productivity increase included intervention group membership (5·25 kg per day [95% CI 4·60–5·91], p<0·0001) and, among intervention participants, older age (p=0·039) and better compliance with the intervention (p<0·0001). Interpretation: A substantial productivity increase was achieved in this rural cohort by providing glasses to correct presbyopia, with little cost and high intervention uptake. Funding: Clearly.http://www.sciencedirect.com/science/article/pii/S2214109X18303292 |
| spellingShingle | Priya Adhisesha Reddy, MBA Nathan Congdon, ProfMD Graeme MacKenzie, DPhil Parikshit Gogate, FRCS (Edin) Qing Wen, PhD Catherine Jan, BOptom (Hon) Mike Clarke, ProfDPhil Jordan Kassalow, OD Ella Gudwin, MA Ciaran O'Neill, ProfPhD Ling Jin, MS Jianjun Tang, PhD Ken Bassett, ProfMD David H Cherwek, MD Rahul Ali, MBBS Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial The Lancet Global Health |
| title | Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial |
| title_full | Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial |
| title_fullStr | Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial |
| title_full_unstemmed | Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial |
| title_short | Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER): a randomised trial |
| title_sort | effect of providing near glasses on productivity among rural indian tea workers with presbyopia prosper a randomised trial |
| url | http://www.sciencedirect.com/science/article/pii/S2214109X18303292 |
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