Assessment of Cataract Surgery Outcome Using the Modified Catquest Short-Form Instrument in China

Ontario Cataract Quality Outcome Initiative: appropriateness and prioritization of cataract surgery

OBJECTIVE

To explore the utility of the Catquest 9SF visual function (VF) questionnaire along with visual acuity (VA) for determining appropriateness and priority for cataract surgery. To evaluate the feasibility of administering the Catquest-9SF in a clinical setting using web-based electronic data capture and interpretation.

DESIGN

Prospective multicentred interventional observational study.

PARTICIPANTS

Subjects undergoing sequential cataract surgery in both eyes at 4 sites in Ontario.

METHODS

We recorded best-corrected VA (BCVA) and VA with current correction (CCVA) in each eye and both eyes (OU) and Catquest-9SF responses on a tablet before and after cataract surgery. Linear regression models were employed to test for associations between VA and visual function (VF).

RESULTS

Preoperative BCVA and CCVA in the worse eye were significant predictors of change in VF (p = 0.006 and p = 0.008, respectively); subjects with worse VA had a greater improvement in VF after surgery. There was a significant association between improvement in VF and improvement in CCVA OU (p = 0.001). Fourteen of 151 subjects (9%) had no improvement or worse VF scores after surgery. Within this group, 10 of 14 subjects had a preoperative score ≤-3, which is suggestive of minimal visual disability. Within this subset, 4 of 14 subjects (2.6%) had a preoperative BCVA of 20/30 or better in their worse eye.

CONCLUSIONS

For patient groups with equal VA, the Catquest-9SF score can help determine priority for surgery. Web-based data capture and interpretation allow for efficient virtual assessments of VF. A BCVA in the worse eye of 20/30 or better combined with a Catquest-9SF score <-3 can be used as a guideline for lowest priority.

The effect of phacoemulsification on visual function among Filipino cataract patients measured by a validated Filipino translation of Catquest-9SF

BACKGROUND

This study developed a validated Filipino version of the Catquest-9SF and administered it to cataract patients pre- and post- surgery.

METHODS

This is a two-phase, single-center, cross sectional, questionnaire type study. The study included participants decked for surgery who are 18 years and above. Sampling was done purposively. The Catquest-9SF questionnaire was translated into Filipino, according to a standard procedure, and validated. The validated version was administered to the participants before and after unilateral cataract surgery. Data were analyzed using Rasch analysis.

RESULTS

Sixty-one patients were enrolled in the study. The preliminary Rasch analysis showed misfit of item 2, which was subsequently excluded from analysis. The remaining eight items showed person separation index of 2.70, reliability coefficient of 0.88, infit of 0.66 to 1.17, outfit of 0.66 to 1.49, observed raw variance explained by measures of 55.3% and eigenvalues of 1.9, 1.4, 1.2, 1.0 and 0.9. There was slightly poor targeting (mean person location 1.24) and multidimensionality but no evidence of differential item functioning (DIF). High internal consistency of items were observed (Cronbach's alpha ≥ 90). Comparison of responses between pre- and post-surgery showed highly significant marginal homogeneity (p < 0.001).

CONCLUSION

The Filipino translation of Catquest-9SF, the Catquest-8SF-PH, was highly valid. It showed improved perceived visual outcomes among Filipino patients post-cataract surgery.

Multi-center validation of Catquest-9SF visual function questionnaire in Ontario, Canada

PURPOSE

To investigate the psychometric performance and responsiveness of Catquest-9SF, a patient-reported questionnaire developed to evaluate visual function as related to daily tasks, in patients referred for cataract surgery in Ontario, Canada.

METHODS

This is a pooled analysis on prospective data collected for previous projects. Subjects were recruited from three tertiary care centers in Peel region, Hamilton, and Toronto, Ontario, Canada. Catquest-9SF was administered pre-operative and post-operatively to patients with cataract. Psychometric properties, including category threshold order, infit/outfit, precision, unidimensionality, targeting, and differential item functioning were tested using Rasch analysis with Winsteps software (v.4.4.4) for Catquest-9SF. Responsiveness of questionnaire scores to cataract surgery was assessed.

RESULTS

934 patients (mean age = 71.6, 492[52.7%] female) completed the pre- and post-operative Catquest-9SF questionnaire. Catquest-9SF had ordered response thresholds, adequate precision (person separation index = 2.01, person reliability = 0.80), and confirmed unidimensionality. The infit range was 0.75-1.29 and the outfit range was 0.74-1.51, with one item ('satisfaction with vision') misfitting (outfit value = 1.51). There was mistargeting of -1.07 in pre-operative scores and mistargeting of -2.43 in both pre- and post-operative scores, meaning that tasks were relatively easy for respondent ability. There was no adverse differential item functioning. There was a mean 1.47 logit improvement in Catquest-9SF scores after cataract surgery (p<0.001).

CONCLUSION

Catquest-9SF is a psychometrically robust questionnaire for assessment of visual function in patients with cataract in Ontario, Canada. It is also responsive to clinical improvement after cataract surgery.

Catquest-9SF questionnaire: Validation in a Greek-speaking population using Rasch analysis

PURPOSE

The Catquest-9SF questionnaire is a tool measuring visual disability and vision-related limitation in patients' daily activities. The primary objective of this study was the validation of Catquest-9SF in a Greek-speaking cataract population.

METHODS

The questionnaire was translated into Greek and translated back into English. A pre-final Greek version was formed and tested by 10 Greek-English bilingual participants and by the translation team, and the final version was produced. Patients scheduled for cataract surgery completed the questionnaire preoperatively and postoperatively. Rasch analysis was performed for the assessment of the Catquest-9SF psychometric properties, including response category ordering, item fit statistics, principal components analysis, precision, differential item functioning and targeting for preoperative and postoperative data collectively.

RESULTS

A total of 100 (55 men, 45 women, mean age = 71.94±6.63) cataract patients completed the Greek version of Catquest-9SF questionnaire preoperatively and postoperatively. Rasch analysis showed a significant improvement in the median person Rasch score from -1.49 preoperatively to -4.71 logits postoperatively, while the effect size was 1.3. Unidimensionality was confirmed since infit and outfit mean square values varied between 0.66 and 1.37. Rasch analysis showed good precision and separation ability (Person Separation Index of 3.28, and Person Reliability of 0.92). Four response categories were found for all items. The item-person means difference was -1.83 logits. The difference between preoperative and postoperative Catquest-9SF logit score was positively correlated with preoperative Catquest-9SF logit score (coeff. = 0.798, p<0.0001) and negatively correlated with postoperative spherical equivalent (coeff. = -0.825, p = 0.011).

CONCLUSION

The Greek version of Catquest-9SF proved to be reliable, valid, unidimensional and responsive to changes after cataract surgery presenting good psychometric properties for cataract patients. Some postoperative mistargeting was found indicating that the tasks were easily performed by respondents after cataract surgery.

TRIAL REGISTRATION

NCT05323526 -retrospectively registered.

Catquest-9SF questionnaire shows greater visual functioning in bilateral cataract populations: A prospective study

Purpose

Visual functioning evaluated by the Catquest-9SF questionnaire has shown to be a valid measure for assessing a patient's prioritization for cataract surgery. This study adapted Catquest-9SF for visual function outcomes post uni-lateral cataract surgery or bi-lateral cataract surgery.

Methods

Visual functioning was assessed before and after uni-lateral or bi-lateral cataract surgery using the Catquest-9SF questionnaire. Patients were enrolled to this study prior to their cataract surgery between March 29 and April 30, 2021 at Shellharbour Hospital, Australia. Catquest-9SF questionnaires were completed prior to and 3 months post surgery. Resulting data were assessed for fit to a Rasch model using WINSTEPS software (version 4.2.0). Catquest-9SF data analysis of Chi-square, Wilcoxon sum test, and Fischer's test were performed in R (version 4.1.0). P value &lt;.05 was considered statistically significant.

Results

Sixty-one patients (mean age = 73.2 years, 62% female) were included for analysis. Catquest-9SF response thresholds, adequate precision (person separation index = 2.58, person reliability = 0.87, Cronbach's alpha = 0.74), uni-dimensionality, and no misfits (infit range 0.65-1.33; outfit range 0.64-1.31) were recorded. The mean of item calibration for patients was -0.22 post-operatively. There was significant (P &lt;.05) improvement (16.3%) in visual functions across all nine Catquest 9-SF items. There was a significant mean visual function difference between patients with uni-lateral (10.1%) and bi-lateral cataract surgery (22.3%) pre-operatively and post-operatively.

Conclusion

The Catquest-9SF questionnaire showed excellent psychometric properties and can assess visual functioning in an Australian population. There was a significant improvement in patient visual function post cataract surgery and higher functioning with bi-lateral cataract surgery.

Psychometric Assessment of the Chinese Version of the Indian Vision Functioning Questionnaire Based on the Method of Successive Dichotomizations

Purpose

The purpose of this study was to assess whether a Chinese translated version of the 33-item Indian Vision Function Questionnaire (IND-VFQ-33) forms a valid measurement scale and to evaluate its psychometric properties based on the method of successive dichotomizations (MSD).

Methods

The English version of the IND-VFQ-33 was translated, back translated, and cross-culturally adapted for use in China. It was interviewer administered to patients with cataracts. MSD, a polytomous Rasch model that estimates ordered thresholds, was used to assess and optimize psychometric properties of the overall scale and three subscales separately.

Results

One hundred and seventy-nine patients provided complete responses. After the removal of 2 misfitting items, a revised 31-item overall scale demonstrated adequate precision (person reliability [PR] = 0.92) and no misfitting items. The general functioning subscale fit the MSD model well after removing two misfitting items. The psychosocial impact subscale and the visual symptoms subscale were not considered further due to poor measurement precision. After addressing psychometric deficiencies, a 31-item overall scale (IND-VFQ-31-CN) and a 19-item general functioning subscale (IND-VFQ-GF-19-CN) were developed.

Conclusions

The original IND-VFQ-33 required re-engineering to form valid measures for use in China. The revised overall scale and general functioning subscale demonstrated adequate MSD based psychometric properties.

Translational Relevance

The revised IND-VFQ-33 is a valid patient-reported outcome assessment for Chinese patients with cataract based on MSD analysis.

Development and Validation of a Questionnaire Assessing Patient Distress from Preoperative Fasting in Cataract Surgery

Purpose: To develop and psychometrically validate a questionnaire to measure patient distress with preoperative fasting related to cataract surgery.Methods: In this single-centered cross-sectional study, consecutive sampling of cataract patients was undertaken immediately preoperatively from February to December 2019. A questionnaire evaluating patient distress with fasting was designed and administered. Questionnaire development occurred in an iterative process and was conducted with consultation from expert investigators and patients. Validation and psychometric evaluation of the questionnaire were performed with Rasch analysis.Results: A preliminary version of the questionnaire was developed by 10 study investigators. Across five iterations of development, the questionnaire was administered to 186 cataract patients. Psychometric evaluation of the 13-item questionnaire demonstrated ordered thresholds, acceptable item calibration and fit, adequate internal consistency, ability to discriminate between three levels of distress from preoperative fasting and no notable differential item functioning. However, issues with mistargeting, clustering of items on the person-item map and multidimensionality remained. Given these concerns, 13 separate re-analyses were conducted via removal of certain items. A 6-item subset was determined to be well targeted, unidimensional, did not display item clustering and was able to discriminate between patients with high and low distress from preoperative fasting.Conclusion: A 6-item questionnaire is a valid, psychometrically robust and reliable measure for the assessment of patient distress with preoperative fasting in cataract surgery. Items include hunger, thirst, hoarseness, weakness, anxiety and nausea. Future studies should seek to validate this questionnaire across a variety of sociodemographic contexts, languages and specialties.

Catquest-9SF questionnaire and eCAPS: Validation in a Canadian population

Background

Visual acuity alone has limitations in assessing a patient’s appropriateness and prioritization for cataract surgery. Several tools, including the Catquest-9SF questionnaire and the electronic cataract appropriateness and priority system (eCAPS) have been developed to evaluate patients–reported visual function as related to day-to-day tasks. The aim of this study was to validate Catquest-9SF and eCAPS in a Canadian population and propose a shorter version of each, in an attempt to extend their applicability in clinical practice.

Methods

The English translation of the Swedish Catquest-9SF and eCAPS were self-administered separately in pre-operative patients in tertiary care in Peel region, Ontario. Rasch analysis was used to validate both scales and assess their psychometric properties, such as category threshold order, item fit, unidimensionality, precision, targeting, and differential item functioning.

Results

A total of 313 cataract patients (mean age = 69.1, 56.5% female) completed the Catquest-9SF and eCAPS. Catquest-9SF had ordered response thresholds, adequate precision (person separation index = 2.09, person reliability = 0.81), unidimensionality and no misfits (infit range 0.75–1.35, outfit range 0.83–1.36). There mean for patients was equal to -1.43 (lower than the mean for items which is set automatically at zero), meaning that tasks were relatively easy for respondent ability. eCAPS had 3 items that misfit the Rasch model and were excluded (infit range 0.82–1.30, outfit range 0.75–1.36). Precision was inadequate (person separation index = 0.19, person reliability = 0.04). 78.8% of subjects scored≤9 (answered that they had no issues for most questions).

Conclusions

Catquest-9SF demonstrated good psychometric properties and is suitable for assessing visual function of care-seeking patients referred for cataract surgery in Ontario, Canada. There was some mistargeting, suggesting that the tasks were relatively easy to perform, which is consistent with previous research. On the contrary, eCAPS is not sensitive in differentiating patients who had impaired visual functioning.

Validation and application of Catquest-9SF in various populations: A systematic review

Cataract is a common cause of reversible blindness. Visual acuity alone is not enough to assess appropriateness for surgery, prioritization, and outcomes. Catquest-9SF questionnaire evaluates patients' self-assessed visual function as related to daily tasks. We summarize and assess the validity of Catquest-9SF as a patient-reported outcome questionnaire to determine its suitability for clinical use. Thirteen studies with sample sizes ranging 102-10,886 (total n = 15,289) undertaken from 2009 to 2018 were included. Catquest-9SF showed unidimensionality, ordered response thresholds, and acceptable precision in all studies. Nine studies had significant mistargeting (range 0.66 to -2.04); the tasks being easy relative to the respondent ability in most studies. Two studies had misfitting items. We conclude Catquest-9SF is a valid and reliable tool to measure visual function in patients with cataract in various populations. Because results can be population specific, it is recommended that Catquest-9SF be validated in a new population before it is incorporated in routine practice.

An alternative application of Rasch analysis to assess data from ophthalmic patient-reported outcome instruments

Purpose

To highlight the potential shortcomings associated with the current use Rasch analysis for validation of ophthalmic questionnaires, and to present an alternative application of Rasch analysis to derive insights specific to the cohort of patients under investigation.

Methods

An alternative application of Rasch analysis was used to investigate the quality of vision (QoV) for a cohort of 481 patients. Patients received multifocal intraocular lenses and completed a QoV questionnaire one and twelve months post-operatively. The rating scale variant of the polytomous Rasch model was utilized. The parameters of the model were estimated using the joint maximum likelihood estimation. Analysis was performed on data at both post-operative assessments, and the outcomes were compared.

Results

The distribution of the location of symptoms altered between assessments with the most annoyed patients completely differing. One month post-operatively, the most prevalent symptom was starbursts compared to glare at twelve months. The visual discomfort from the most annoyed patients is substantially higher at twelve months. The current most advocated approach for validating questionnaires using Rasch analysis found that the questionnaire was “Rasch-valid” one month post-operatively and “Rasch-invalid” twelve months post-operatively.

Conclusion

The proposed alternative application of Rasch analysis to questionnaires can be used as an effective decision support tool at population and individual level. At population level, this new approach enables one to investigate the prevalence of symptoms across different cohorts of patients. At individual level, the new approach enables one to identify patients with poor QoV over time. This study highlights some of the potential shortcomings associated with the current use of Rasch analysis to validate questionnaires.

Re-engineering the Hong Kong Quality of Life Questionnaire to Assess Cataract Surgery Outcomes

PURPOSE

To assess psychometric properties of the Hong Kong Quality of Life Questionnaire (HKQ) using Rasch analysis and use it to assess cataract surgery outcomes.

METHODS

The HKQ was interviewer administered to participants at baseline (preoperative) and 12 months of follow-up (postoperative). Rasch analysis was used to assess and improve psychometric properties of the HKQ using the preoperative data. The responsiveness of the HKQ was assessed on the stacked preoperative and postoperative data, reported with the effect size.

RESULTS

One hundred ninety-nine participants (median age: 72 years; interquartile range: 65 to 78 years) with cataract completed the HKQ at the preoperative assessment. There were more women (58%) and most of the participants had bilateral cataract (83.9%). Nearly half of the participants had undergone surgery in one eye (45.2%) followed by bilateral surgery (38.7%). Psychometric assessment guided by Rasch analysis resulted into a 15-item HKQ with promising psychometric properties including adequate measurement precision (2.09), no misfitting items, near perfect targeting (-0.05), unidimensionality, and with no evidence of item bias. For those who completed the HKQ (n = 82, 41.2%) at the 12-month follow-up visit, all groups demonstrated statistically significant gains in the HKQ scores, with the highest gain in participants who had undergone bilateral surgery (effect size: 2.61).

CONCLUSIONS

The 15-item HKQ was valid and psychometrically sound and might be a highly responsive instrument to measure cataract surgery outcomes in China. This study demonstrated that cataract surgery significantly improves quality of life in the Chinese population. [J Refract Surg. 2018;34(6):413-418.].

The Chinese Catquest-9SF: validation and application in community screenings

Background

The purpose of this study was to validate the Chinese Catquest-9SF questionnaire in community screenings and explore the correlation between Catquest-9SF scores and Lens Opacities Classification System (LOCS) III cataract grading.

Methods

This was a prospective questionnaire validation study. The Catquest-9SF questionnaire was translated into Chinese and was completed by 104 Chinese cataract patients who were diagnosed in community screening. Rasch analysis was used to assess its psychometric properties, and Spearman correlation coefficient was employed to determine the correlation between Catquest-9SF scores and LOCS III cataract grading.

Results

The Catquest-9SF questionnaire demonstrated ordered response categories and unidimensionality (item fit statistics range: 0.70–1.35); the PSI and PR of the category probability curves were 2.00 and 0.80, respectively. There was a fair but statistically significant correlation between Catquest-9SF (Q6, Q7, and Q8) and LOCS III scores and a moderate correlation between Q4 in Catquest-9SF and subcapsular components for the better eye (r = − 0.546, p < 0.001).

Conclusion

The Chinese version of Catquest-9SF is a valid and reliable questionnaire in community screenings. Thus, this questionnaire may be expected to be an auxiliary tool for preliminary cataract screening use.