Does optometrists' self-reported practice in glaucoma detection predict actual practice as determined by standardised...

Area of Science:

• Ophthalmology and Optometry
• Health Services Research

Background:

• Questionnaires are frequently used to assess clinical practice but are prone to self-reporting bias.
• This bias can lead to inaccurate representations of actual healthcare delivery, particularly in specialized fields like glaucoma detection.

Purpose of the Study:

• To evaluate the accuracy of self-reported data on optometrist practices for glaucoma case-finding.
• To assess the validity of questionnaires in measuring the appropriate referral of patients suspected of having glaucoma.

Main Methods:

• A dual-approach methodology was employed, combining Standardised Patient (SP) visits with interviews for a sample of optometrists (N=34).
• A national survey (N=1264) compared optometrists' reported referral information for suspected glaucoma with actual referral letters (N=571).
• Chi-square analysis was used to quantify the correspondence between reported and actual practices.

Main Results:

• The SP study showed poor agreement between questionnaires and observed practice for history, intra-ocular pressure (IOP), and visual fields, but good agreement for routine ocular health and refraction.
• The referral study found correspondence only for IOP, with no agreement on disc assessment, visual fields, or family history.
• Self-reported data consistently overestimated the performance of routine tests.

Conclusions:

• Self-reported clinical practice by optometrists tends to overestimate the frequency of routine glaucoma diagnostic tests.
• While mandatory tests showed better correspondence, discretionary tests exhibited significant discrepancies between reported and actual practice.
• These findings necessitate caution when interpreting questionnaire-based studies on current glaucoma case-finding practices.