Article Text

Download PDFPDF
Using incognito standardised patients to evaluate quality of eye care in China
  1. Jingchun Nie1,
  2. Lifang Zhang1,
  3. Jiayuan Gao1,
  4. Jason Li2,
  5. Qian Zhou1,
  6. Yaojiang Shi1,
  7. Sean Sylvia3,
  8. Nathan Congdon4,5
  1. 1 Center for Experimental Economics in Education, Shaanxi Normal University, Xi'an, Shaanxi Province, China
  2. 2 Harvard Medical School, Harvard University, Boston, Massachusetts, USA
  3. 3 Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
  4. 4 Centre for Public Health, Queen's University Belfast, Belfast, Belfast, UK
  5. 5 Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
  1. Correspondence to Dr Sean Sylvia, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; sean_sylvia{at}


Background/aims Few studies have objectively examined the quality of eye care in China. We assessed refractive care using the incognito standardised patient (SP) approach, a gold standard for evaluating clinical practice.

Methods A total of 52 SPs were trained to provide standardised responses during eye examinations, and underwent automated and non-cycloplegic, subjective refraction by a senior ophthalmologist from Zhongshan Ophthalmologic Center, a national-level clinical and research centre. SPs subsequently received subjective refraction and eye exams at a randomly selected sample of 40 public hospitals and 93 private optical shops in Shaanxi, Northwestern China. Difference between expert and local refraction in the better-seeing eye was calculated by the vector diopteric method, and completeness of exams assessed against national standards. SP and provider demographic information and provider clinical experience were recorded.

Results SPs (n=52, mean (range) age, 25.7 (22–31) years, 28.8% male) underwent 133 eye exams (mean total duration 15.0±11.7 min) by 133 local refractionists (24–60 years, 30.3% male). Only 93 (69.9%), 121 (91.0%) and 104 (78.2%) of local refractionists assessed vision, automated and subjective refraction, respectively. The median inaccuracy was −0.25 diopters (D), while 25.6% of results differed by an absolute value of ≥1.0 D and 6.0% by ≥2.0 D. Predictors of inaccurate refraction included spectacle power <−6.0 D (OR=2.66; 95% CI, 1.27 to 5.56), service at a public (vs private) hospital (OR=2.01; 95% CI, 1.11 to 3.63) and provider male sex (OR=2.03; 95% CI, 1.11 to 3.69).

Conclusion Inaccurate refractions are common in Northwestern China, particularly in public facilities. Important assessments, including subjective refraction, are frequently omitted.

  • optics and refraction
  • diagnostic tests/investigation
  • public health
  • treatment other

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Twitter @sean_sylvia

  • Correction notice This paper has been amended since it was published online. There was an error in seventh author's surname and first name which had been transposed.

  • Contributors YS came up with the concept for this study and designed the study. LZ, JG and QZ set up the study, collected the data and analysed the data. JN and JL drafted the first draft of the paper. SS and NC reviewed and suggested the structure of the manuscript. All authors contributed to the follow-up of the study and the interpretation of the data, and critically reviewed the manuscript.

  • Funding This study is supported by the Ministry of Education’s 111 Project (Grant number: B16031). NC is funded by the Ulverscroft Foundation (UK).

  • Competing interests NC is the director of Research for Orbis International, New York, USA, an organisation involved in promoting eye health in low-resource settings.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.

Linked Articles

  • At a glance
    Keith Barton James Chodosh Jost B Jonas