Validation of Catquest-9SF in Danish: developing a revised form of the Catquest-9SF - the Danish Catquest-7SF.

The primary goal was to validate a Danish translated version of the Catquest-9SF by Rasch analysis. The secondary goal was to investigate whether preoperative Catquest-9SF scores, best-corrected visual acuity, comorbidity, gender, age or corneal astigmatism could predict improvements in subjective outcome. In a prospective trial, 250 patients eligible for cataract surgery were included. Patients filled out the translated Catquest-9SF questionnaire before surgery and again 3 months after surgery. Both preoperative and postoperative questionnaires were included in the Rasch analysis. A multiple reverse stepwise regression model was used to investigate the correlation between preoperative measurements and subjective improvement. The preliminary Rasch analysis showed misfit of items 4 and 6. These items were removed, and the remaining seven items demonstrated a measurement precision of 2.78, a person reliability coefficient of 0.89, ordered response categories, infit of 0.69-1.22, outfit of 0.73-1.14, observed raw variance explained by measures of 70.4% and an eigenvalue of 1.7. Item 7 showed a mild DIF for gender (0.54 logits), and person mean Rasch score targeting was -1.69 logits. Preoperative Catquest score was the only parameter with a significant correlation to a gain in subjective outcome (p < 0.001). A preoperative Catquest-9SF score of 0.5 carried a 95% likelihood of an increase in subjective outcome. The Danish version of the Catquest-9SF fit the Rasch model. Only preoperative Catquest-9SF score was correlated to subjective improvement, and a cut-off value of 0.5 predicted an improvement in subjective outcome with 95% probability.

Nielsen E ，Lundström M ，Pesudovs K ，Hjortdal J ... -  《-》

Catquest-9SF patient outcomes questionnaire: nine-item short-form Rasch-scaled revision of the Catquest questionnaire.

Lundström M ，Pesudovs K 《-》

Catquest-9SF questionnaire: validation of Malay and Chinese-language versions using Rasch analysis.

Adnan TH ，Mohamed Apandi M ，Kamaruddin H ，Salowi MA ，Law KB ，Haniff J ，Goh PP ... -  《Health and Quality of Life Outcomes》

Validation of Catquest-9SF-A Visual Disability Instrument to Evaluate Patient Function After Corneal Transplantation.

Claesson M ，Armitage WJ ，Byström B ，Montan P ，Samolov B ，Stenvi U ，Lundström M ... -  《-》

The outcome of cataract surgery measured with the Catquest-9SF.

The purpose of this study was to use the Catquest-9SF to measure cataract surgery outcomes, and to use Rasch analysis to test the psychometric properties of this questionnaire, including its validity and responsiveness. Patients were recruited as consecutive cataract surgery patients during 1 month at six surgical units in Sweden (via the National Cataract Register). The patients completed the questionnaire before surgery and 3 months after. The Catquest-9SF data were assessed for fit to the Rasch model using version 3.63.2 of the WINSTEPS software (Winsteps.com, Beaverton, OR, USA). Both preoperative and postoperative questionnaires were included in the analysis. The responsiveness to cataract surgery was calculated as the effect size. Completed questionnaires before and after surgery were received from 846 patients. The Rasch analysis showed that the category thresholds were ordered. All items fit a single overall construct (infit range 0.79-1.40; outfit range 0.74-1.40). The ability to discriminate different strata of person ability was good, with a real patient separation of 2.58 and patient separation reliability of 0.87. The questionnaire showed unidimensionality and was largely free from differential item functioning. The item difficulty was reasonably well targeted to both preoperative and postoperative patient ability. The Catquest-9SF Rasch score correlated significantly with visual acuity, and cataract surgery resulted in a significant improvement with an effect size of 1.8. The Catquest-9SF shows excellent psychometric properties, as demonstrated by Rasch analysis. It is highly responsive to cataract surgery, and its brevity (nine items) makes it well suited for use in daily clinical practice.

Lundstrom M ，Behndig A ，Kugelberg M ，Montan P ，Stenevi U ，Pesudovs K ... -  《-》