Self-assessed visual function outcome in cataract surgery: minimum important difference of the Catquest-9SF questionnaire.

BACKGROUND: The purpose of this study was to study the minimum important difference (MID) of the Catquest-9SF questionnaire in cataract surgery. METHODS: A nationwide multi-center prospective randomized study was conducted using the Swedish National Cataract Register and the Catquest-9SF questionnaire. Randomized patients (n = 400) who had completed the Catquest-9SF before surgery and three months after surgery were sent an anchor question on self-assessed change in visual function after cataract surgery 14 days after the postoperative Catquest-9SF. Rasch analysis was performed on the preoperative and postoperative Catquest-9SF questionnaires, and the patients were dichotomized with regard to their preoperative Rasch score. The MID range of the two groups was calculated based on the anchor question, and the anchor question based MID was then estimated in a scatter plot. The MID was also estimated based on distribution by calculating Cohen's effect size. RESULTS: The analyses included 231 patients who had completed the Catquest-9SF on both occasions as well as the questionnaire with the anchor question. The group with better preoperative visual function had an anchor question based MID of - 0.5 and a Cohen's effect size based MID of - 1.07. The group with worse preoperative visual function had an anchor question based MID of - 1.80 and a Cohen's effect size based MID of - 1.46. CONCLUSION: This article contributes detailed knowledge of the MID of Catquest-9SF, enabling even more accurate high-quality evaluation of the outcome and benefit of cataract surgery worldwide.

Patient-reported visual function outcome in cataract surgery: test-retest reliability of the Catquest-9SF questionnaire.

PURPOSE: To study the test-retest reliability of the Catquest-9SF questionnaire in cataract surgery. METHODS: A single-centre prospective non-randomized test-retest study was conducted using the Swedish National Cataract Register and the Catquest-9SF questionnaire, which is a valid patient-reported outcome measurement tool developed and used for evaluating quality and visual disability outcome in cataract surgery. Consecutive patients (n = 144) scheduled for cataract surgery completed the Catquest-9SF twice before surgery, with a minimum of 7 days and a maximum of 14 days between the two questionnaires. A rating scale model was constructed on the basis of the questionnaires from the first measurement and used to generate scores for both the first and second measurements. The consistency was investigated by calculating intraclass correlation, Pearson correlation and a Bland-Altman plot. Internal consistency was measured using Cronbach's alpha. RESULTS: Analyses showed an intraclass correlation of 0.93 (95% confidence interval: 0.90-0.95), a Pearson correlation of 0.93 and Cronbach's alpha of 0.94. The results fit well in a Bland-Altman plot. CONCLUSION: The test-retest reliability of the Swedish Catquest-9SF is excellent. Along with previous knowledge, this supports continued use of the Catquest-9SF in evaluating quality and outcome in cataract surgery.

Intraoperative difficulties, complications and self-assessed visual function in cataract surgery.

PURPOSE: To study associations between intraoperative difficulties and changes in patient-perceived and postoperative visual function and visual satisfaction after cataract surgery. METHODS: Swedish multicenter, prospective, cross-sectional, nonrandomized, National Cataract Register study. A total of 10 979 patients (n = 10 979) who underwent cataract surgery from 2008 to 2011 completed the Catquest-9SF questionnaire before and 3 months postoperatively. Using Rasch analysis, we converted the nonparametric grading of the answers to parametric data and performed parametric statistical analyses. Multiple regression models were used to examine possible predictors associated with self-assessed visual function after cataract surgery. RESULTS: Greater improvement in self-assessed visual function was seen in patients in whom trypan blue dye was used; those without a posterior capsular tear or an ocular comorbidity; and those who were younger, female and had low preoperative corrected distance visual acuity (CDVA) or high postoperative CDVA compared with their counterparts. Significantly higher self-assessed postoperative visual function was seen in patients in whom trypan blue dye was used and those with no posterior capsular tear or ocular comorbidity and no use of capsular hooks; and those who were younger and had low preoperative or high postoperative CDVA compared with their counterparts. The risk of general dissatisfaction after cataract surgery was significantly greater in patients with a posterior capsule tear, ocular comorbidity or low postoperative CDVA, and those in whom mechanical pupillary stretching was performed. CONCLUSION: Several intraoperative difficulties, posterior capsular tear, ocular comorbidity, age, gender, and preoperative and postoperative CDVAs affect patient improvement and self-assessed visual function after cataract surgery.

Ocular comorbidity and self-assessed visual function after cataract surgery.

PURPOSE: To study the association between ocular comorbidities and the change in patient-perceived visual function, postoperative patient-perceived visual function, and visual satisfaction after cataract surgery. SETTING: Forty-one Swedish cataract surgical units. DESIGN: Clinic-based cross-sectional study. METHODS: Patients who had cataract surgery from 2008 to 2011 completed the Catquest-9SF questionnaire preoperatively and 3 months postoperatively. Questionnaire data were converted into interval data using Rasch analysis. Multiple regression and logistic regression models were used to examine possible predictors associated with self-assessed visual function after cataract surgery. RESULTS: The total questionnaire was completed by 10,364 patients. Patients without diabetic retinopathy, corneal guttata, glaucoma, macular degeneration, any other comorbidity, or the presence of more than 1 ocular comorbidity had greater improvement in self-assessed visual function than their counterparts. Patients with other factors such as young age, female sex, short preoperative surgical waiting time, and low preoperative and high postoperative corrected distance visual acuities (CDVAs) also had significantly greater improvement in self-assessed visual function than their counterparts. Young patients and those with no specific ocular comorbidities, a short surgical waiting time, and low preoperative and high postoperative CDVAs had significantly higher self-assessed postoperative visual function than their counterparts. Patients without the mentioned ocular comorbidities and a high postoperative CDVA had a higher odds ratio of general satisfaction rather than dissatisfaction than their counterparts. CONCLUSIONS: Multiple ocular comorbidities, age, preoperative waiting time, and preoperative and postoperative CDVAs affected patients' improvement and self-assessed visual function after cataract surgery. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.