Patient-reported outcome measures

Large-scale data collection shows why patients may be unhappy after surgery

Aidan Hanratty

Posted: Saturday, September 1, 2018

Professor Mats Lundström

Taking account of patient-reported outcome measures can help improve overall clinical outcomes, Professor Mats Lundström told the 22nd ESCRS Winter Meeting in Belgrade, Serbia. He described a variety of approaches to measuring data and how best to measure patient-reported outcomes.

The goal is to compare patient-reported outcomes with clinically reported outcomes, seeing how and why discrepancies between the two may arise.

Questionnaires are formulated with great attention paid to varying items, such as the degree of difficulty a patient faces in performing various tasks. The questionnaires follow the Rasch model of item response theory, which helps create interval data to differentiate between different strata of patients.

In the case of the Catquest-9SF study, a nine-item, short-form questionnaire for measuring patient-reported outcomes of cataract surgery, questions were asked on the difficulty of different tasks: from reading text in newspapers and watching television to recognising faces in the street and reading the price of goods while shopping. Also considered was satisfaction with sight preoperatively, across a range of four options. The same questions were then asked after surgery.

The results showed that in most cases – 90.5% – both clinically reported outcomes and patient-reported outcomes were positive. In 1.7% of cases clinical outcomes were negative while patients were happy with their postoperative vision. In just 0.5% of cases both clinical and personal outcomes were poor, while in 7.4% of cases, clinically reported outcomes were positive, but patients were unhappy.

Prof Lundström explained that upon investigation of the data, researchers learned that many of these patients were most likely myopic before surgery, with good reading ability. After surgery they were rendered emmetropic, so they could read the chart, but were unable to read up close without glasses, which they could do before surgery.

Such discrepancies arise when doctors look at what they regard as excellent clinical outcomes without taking into account the patient’s own expectations and requirements.

Prof Lundström described the various methods of data collection, detailing optimal timing and patients for selection. Examining the data, he showed how one clinic had problems related to complications during surgery or anisometropia: “They operate in one eye and then waited half a year and then took the other eye, and if you live for half a year with anisometropia and answer the questionnaire you are not happy.”

About 7,000 questionnaires are completed each year in the National Swedish Registry, with postoperative responses from 75-80% of these. The results are published openly, so that all participating clinics can see where they fare. “No one wants to be in the lower end of the outcome. So, it’s a good thing.”

Mats Lundström:

The European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) has included Catquest-9SF for cataract surgery and QIRC for refractive surgery and all ESCRS surgeons are welcome to join and test their patients’ opinion about the outcome to be compared with the clinical outcome