Evidence map›Paper›PMID 33233981›Full record

Trial reportInquiry : a journal of medical care organization, provision and financing

What Can Children Learn from a Free Trial of Eyeglasses Use? Evidence from a Cluster‑Randomized Controlled Trial in Rural China.

Yaojiang Shi, Wei Nie, Ming Mu, Shuyi Song, Lanxi Peng, Lifang Zhang, Jie Yang, Hongyu Guan, Yiqi Zhu, Qiufeng Gao and 1 more

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Inquiry : a journal of medical care organization, provision and financing. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Myopia and Depression among Middle School Students in China-Is There a Mediating Role for Wearing Eyeglasses?International journal of environmental research and public health · 2022
    Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Yaojiang ShiCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Wei NieCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Ming MuCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Shuyi SongCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Lanxi PengCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Lifang ZhangCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Jie YangCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Hongyu GuanCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Yiqi ZhuBrown School, Washington University in St. Louis, Missouri, USA.
Qiufeng GaoCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.
Jingchun NieCenter for Experimental Economics in Education, Shaanxi Normal University, Xi'an, China.ORCID 0000-0002-7006-5796

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Free trial is a widely used business strategy that takes advantage of information asymmetry. However, evidence on what we can learn and how rapidly we can learn from a free trial of health care is limited. This study evaluates the effect of a free trial of eyeglasses on children's 8 items of perception related to eyeglasses use. An evaluation was conducted alongside a cluster-randomized controlled trial involved 832 myopic children from northwest rural China. A total of 428 myopic children from 42 schools were randomized to receive free eyeglasses, and 404 myopic children from 42 schools were randomized as control group. We find that the perceived costs and benefits of eyeglasses use and the perceived timing of wearing eyeglasses at the appropriate time can be learned from a free trial of eyeglasses. Compared with the control group in the long run, 5.6 percentage points more children in treatment group agreed that wearing eyeglasses was attractive, 16.5 percentage points more children agreed that wearing eyeglasses is helpful to academic performance, and 7.9 percentage points more children agreed that children with vision problems should wear eyeglasses. Due to the effects of a free product and the time to learning from experience, the magnitude of the impact of a free trial changed over time. We also find that the indirect experience, such as a vision protection course, cannot change children' perceptions about the cost or benefits of eyeglasses use. The findings imply that children can learn significantly from the experience of a free trial of eyeglasses. A free trial is an effective strategy to solve the information asymmetry problem for health care. The first pair of eyeglasses of children can be one-off subsidized to trigger demand for eyeglasses use.

Indexed as

EyeglassesRural PopulationChildChinaCommerceDelivery of Health CareHumansexperience attributeseyeglasses usefree trailinformation asymmetryrural China

Identifiers

PMID33233981
PMCPMC7691910

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.