Objective To investigate the discrepancy between patient-reported symptoms and measured clinical findings and influencing factors in dry eye (DE).

Setting A population-based, cross-sectional study was performed in July–August 2007 in northeast China. The study was performed on populations originating from two rural districts that are respectively located approximately 377 and 177 km from our hospital.

Participants 2600 eligible residents from 1300 households were identified; valid responses were obtained from 2262 residents (mean age 48 (range 12–88) years; 926 men and 1336 women; response rate 87%).

Primary outcome measures Patient-reported symptoms of DE, tear film break up time (BUT) and Schirmer scores (Schirmer II).

Results Subjects with normal BUT and Schirmer scores without any DE symptoms were defined as the control group. Those with abnormal BUT and Schirmer scores and symptoms of DE were defined as the DE group. Subjects with disparities between the occurrence of DE symptoms and measured clinical findings were regarded as the discrepancy. Out of 2262 subjects, the discrepant group contained 960 subjects (42.44%) with significant difference (χ²=4.027, p=0.045<0.05). Factors that influenced the subjective reporting of DE symptoms included gender, smoking status, environment and age. Schirmer II test and tear film BUT values were remarkably different among control, DE and discrepant groups.

Conclusions Development of DE can be related to many factors. It is of great importance to put forward the preclinical phase concept (patients who are symptomatic for DE and yet show no aqueous deficiency or evaporative signs) and to screen outpatients with DE-inducing features. Future interventions should focus on patients demonstrating a discrepancy between self-reported symptomology and measured clinical findings.