A head-to-head comparison of 16 cataract surgery outcome questionnaires.

To investigate the responsiveness of 16 questionnaires used in cataract surgery outcomes. Prospective, observational study. Patients at the Ophthalmology Eye Clinic, Flinders Medical Centre, Adelaide, Australia, and 1 matched eye clinic in Sweden. Sixteen Rasch-scaled cataract surgery questionnaires were completed before and 6 months after surgery. These were: the Cataract Symptom Scale, 6 versions of the National Eye Institute Visual Function Questionnaire, the Quality of Life and Vision Function Questionnaire, the Cataract TyPE Specification, the Visual Activities Questionnaire, the Visual Disability Assessment (VDA), the Visual Function and Quality of Life questionnaire, the Visual Function Index, Catquest-9SF, the Visual Symptoms and Quality of Life questionnaire, and the Cataract Outcomes Questionnaire. Responsiveness was calculated with the effect size (ES) statistic (change in questionnaire score divided by pooled standard deviation of the preoperative and postoperative scores). Questionnaire responsiveness to cataract surgery (ability to detect clinically important change). All 16 questionnaires and their subscales were responsive to cataract surgery, with visual functioning scales being more responsive than socioemotional scales and some subscales being less responsive. The largest ES was for the Catquest-9SF (1.45; 95% confidence interval [CI], 1.22-1.67), which was the only instrument with a mean and 95% CI of more than 1.0 (very large ES). Three measures had very large ESs and 95% CIs of more than 0.80 (large ES): the VDA (activity limitations and subscale) and the Cataract Outcomes Questionnaire, although their 95% CIs overlapped with a number of other instruments. The Catquest-9SF is short and highly responsive to cataract surgery, and so is ideal for measuring visual functioning outcomes. Other instruments may be preferred to measure different constructs. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

McAlinden C ，Gothwal VK ，Khadka J ，Wright TA ，Lamoureux EL ，Pesudovs K ... -  《-》

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

Lundström M ，Pesudovs K 《-》

Measuring outcomes of cataract surgery using the Visual Function Index-14.

To determine which version of the Visual Function Index-14 (VF-14) most precisely measured cataract surgery outcomes, rescale the VF-14 using Rasch analysis, and create a short-form version for comparison. Flinders Medical Centre, Adelaide, South Australia, Australia. In this cohort study incorporating questionnaire development, participants were drawn from the cataract surgery waiting list at Flinders Medical Centre. There were 2 cohorts: a preoperative cohort used for questionnaire development and an outcomes cohort. All patients had cataract surgery by phacoemulsification with intraocular lens implantation. Rasch analysis was used to refine the VF-14 into valid long-form (VF-11R) and short-form (VF-8R) versions. The ability of 8 versions (original; 2 proposed versions; 5 previously proposed versions) of the VF-14 to discriminate cataract surgery outcomes was compared with that of the standard VF-14 using the relative precision method. The preoperative cohort comprised 210 patients and the outcomes cohort, 51 patients. Large gains in visual functioning occurred with cataract surgery, and these were detectable with all versions of the VF-14. The largest gain in precision, 125% (relative precision. 2.25), occurred for VF-8R. Short forms that were not Rasch scaled showed gains in precision, from 23% to 80%. The VF-8R also showed the largest gains in precision in 2 subgroups: with ocular comorbidity (relative precision, 2.14) and without ocular comorbidity (relative precision, 2.48). Results show an unequivocal advantage to using Rasch-scaled scores for assessing cataract surgery outcomes. The 8-item, Rasch-scaled VF-8R appears ideally suited for measuring cataract surgery outcomes given its high precision and short test time. No author has a financial or proprietary interest in any material or method mentioned.

Gothwal VK ，Wright TA ，Lamoureux EL ，Pesudovs K ... -  《-》

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 ... -  《-》

Study of possible predictors associated with self-assessed visual function after cataract surgery.

To determine the preoperative or postoperative patient-related factors that make patients benefit more or less from cataract surgery. Multicenter, prospective, cross-sectional Swedish National Cataract Register study. A total of 14 817 patients who underwent cataract surgery from 2000 to 2006 in 42 Swedish ophthalmology departments. The patients completed the Catquest questionnaire before and 6 months postoperatively. The 9 questions in the revised Catquest-9SF were selected from the Catquest and recoded by Rasch analysis, which makes it possible to use parametric statistics when analyzing the study data. The change from preoperative to postoperative, the postoperative mean subjective visual function, and satisfaction with vision were assessed with multiple regression or logistic regression with dummy variables where appropriate, in relation to waiting time, age, preoperative and postoperative corrected distance visual acuity (CDVA), ocular comorbidity, a first- or second-eye surgery, gender, achieved postoperative refraction, correct sign biometry prediction error, and absolute biometry prediction error. Three outcome measures from Catquest-9SF of patient self-assessed visual function after cataract surgery. Young age (P<0.001), low preoperative CDVA (P<0.001), high postoperative CDVA (P<0.001), no ocular comorbidity (P<0.001), and postoperative myopia (-2 to 0 diopters [D]) instead of hyperopia (>0 to +2 D; P<0.05) led to significantly greater improvement in subjective visual function and a better postoperative subjective visual function than the counterparts. Women (P<0.001) and patients who underwent a first-eye surgery (P<0.001) had greater improvement but lower postoperative subjective visual function (P<0.001) than men and patients who underwent a second-eye surgery. A correct sign biometry prediction error of plus instead of minus led to greater improvement in subjective visual function (P<0.01) but no difference in postoperative subjective visual function. The absolute biometry prediction error had no effect on the change in subjective visual function, the subjective mean visual function or satisfaction with vision. Several patient preoperative and postoperative factors are related to the self-assessed benefit of cataract surgery. Age, preoperative and postoperative CDVAs, ocular comorbidity, a first- or second-eye surgery, gender, and achieved postoperative refraction were related to changes in subjective visual function, subjective visual function, and satisfaction with vision.

Rönbeck M ，Lundström M ，Kugelberg M 《-》