Patient-reported outcomes measure after cataract surgery using the Catquest-9SF questionnaire in a U.S. Veterans Health Administration population

U.S. Veteran patients reported significant qualitative improvements in vision-related daily tasks postcataract surgery in Catquest-9SF survey responses. This study supports the utility of Catquest-9SF surveys in large-scale Veteran healthcare settings.

Abstract

Purpose:

To validate the Catquest-9SF survey in a U.S. Veteran population while assessing how cataract surgery affects quality of life from the patient's perspective.

Setting:

Edward Hines Jr. VA Hospital, Hines, Illinois.

Design:

A prospective survey study of Veteran patients undergoing cataract surgery, gauging preoperative and postoperative responses to questions regarding vision-related daily tasks.

Methods:

Recruitment selected for all Veteran patients undergoing routine cataract surgery without a second simultaneous ophthalmic surgery. Patients who experienced complications during surgery were excluded. Outcomes were measured using the Catquest-9SF questionnaire and postoperative visual acuity.

Results:

257 Veterans were included in this study. Rasch person-measure estimates improved from −1.37 to −4.22 logits (Δ 2.85 logits), indicating higher visual functioning after cataract surgery. The Catquest-9SF demonstrated satisfactory Rasch performance (ordered thresholds, person reliability 0.83, person-separation 2.25, first contrast eigenvalue 1.65). Mean logMAR visual acuity improved from 0.41 ± 0.34 to 0.18 ± 0.22 (mean change −0.23; P < .01).

Conclusions:

To the authors' knowledge, this is the first use of the Catquest-9SF questionnaire as a patient-reported outcomes measure tool to investigate cataract surgery outcomes among U.S. Veterans. This study found that the Catquest-9SF satisfied validation criteria in a U.S. Veteran population and found cataract surgery to improve patient-reported outcomes, regardless of comorbidity.

Visual impairment due to cataracts is a major public health concern in the aging population, and cataract surgery is one of the most commonly performed surgeries worldwide.¹ Although traditional outcome measures for cataract surgery include corrected distance visual acuity and refractive error, there has been a growing emphasis on incorporating patient-reported outcomes measures (PROMs) to better evaluate the impact of cataract surgery on daily life.² PROMs have gained increasing importance in recent years as a tool to evaluate the effectiveness of a wide variety of medical procedures and treatments. The use of PROMs can provide valuable information on the functional and quality of life outcomes of cataract surgery, which can inform clinical decision-making, improve patient-centered care, and help generate more accurate indications for clinical trials.³

Various survey methods, such as the Visual Function Index-14 (VF-14), the Visual Function Index-8 (VF-8), the Cataract Symptom Score (CSS), the Activities of Daily Vision Score (ADVS), Catquest, and Rasch-scaling, have been used as PROMs to gauge the benefits of cataract surgery on quality of life, with particular emphasis on patient-reported visual outcomes. Recent literature underscores the reliability and responsiveness of the Catquest-9SF questionnaire method in evaluating cataract surgery outcomes.^4,5 A study using the Catquest-9SF method to assess 870 cataract operations in 5 Dutch hospitals from 2014 to 2015 showed an improvement in functioning and further demonstrated the usefulness of the survey method as a way to complement clinical parameters to inform patient-centered approaches in clinical practice.⁶

When assessing the value of health care, clinicians have traditionally relied on a set of quality metrics defined by laboratory values (eg, hemoglobin A1c levels for diabetes), testing (eg, visual acuity), complication rates, etc., but these metrics are rarely the most valuable measures of success from the patient perspective. Instead, patients prioritize outcomes that affect their daily lives, such as independence, engagement in activities, and family care. To measure healthcare outcomes from the patient's perspective, PROMs are necessary to provide data showing how procedures directly affect activities of daily living. Furthermore, PROMs can inform patient–clinician communication around goals of care and change how patients interpret their condition.⁷

The Catquest-9SF questionnaire has shown to be a validated tool outside of the United States that assesses vision-related quality of life after cataract surgery in a responsive manner.^4,5 The questionnaire is composed of 9 questions based on a set of factors commonly indicative of quality of daily life. There is limited research on the use of PROMs in a Veterans Affairs (VA) population. Therefore, as the Catquest-9SF questionnaire has not been used specifically in either a U.S. or VA population, this study aims to validate its use in a new setting. Furthermore, our secondary aim is to investigate how cataract surgery affects quality of life from the patient's perspective in a U.S. VA population using an internationally validated questionnaire.

METHODS

Institutional Review Board (IRB) approval was obtained from the Edward Hines VA Hospital IRB. The study followed the tenets of the Declaration of Helsinki and HIPAA regulations, and informed consent was obtained from the participants after explanation of the nature and possible consequences of the study.

There were 257 Veterans recruited for the study. Recruitment occurred between June 2023 and June 2024 at the Edward Hines, Jr. VA Hospital. All patients undergoing routine cataract surgery without a second simultaneous ophthalmic surgery were recruited for the study (eg, cataract surgery with combined glaucoma procedures were not included). Patients scheduled for corrective cataract surgery after complication and those who experienced complications during surgery were excluded.

We targeted a sample of approximately 300 participants to ensure stable Rasch calibration and person-measure precision, consistent with previous Catquest-9SF validation studies and Rasch measurement guidance.^8–10 Linacre notes that for 99% confidence within ±0.5 logits, samples of approximately 108 to 243 may be required, with ∼250 or more recommended for high-stakes or definitive calibration.¹¹ Accordingly, our final analytic sample of 257 participants meets these recommended thresholds. Forty-three participants were excluded because of missing postoperative responses or loss to follow-up. Although comorbidities were examined, these subgroup analyses were exploratory and not specifically powered for hypothesis testing.

The English version of the Catquest-9SF questionnaire was used to survey the participating patients. The questionnaire is composed of 9 questions that include 2 global assessment questions and 7 daily-life questions (Appendix 1, available at http://links.lww.com/JRS/B553). The first global assessment assesses difficulties and has responses ranging from 1 = “No, no difficulty” to 4 = “Yes, very great difficulty.” The second global assessment assesses satisfaction and has responses ranging from 1 = “Very Satisfied” to 4 = “Very Dissatisfied.” The 7 daily-life satisfaction questions have the same responses and response range as the first global assessment question.

Study nurses administered the questionnaire by phone 1 week preoperatively and again 3 months postoperatively. Patients were categorized into groups including first cataract procedure and second cataract procedure. In addition, patient demographics, presurgery and postsurgery visual acuity, type of intraocular lens (IOL) used, and history of existing illness including diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma were collected from the patients' medical records.

Analysis

The psychometric properties of the Catquest-9SF in a study on Veteran patients from Chicago were assessed by Rasch analysis. Rasch analysis estimates the level of difficulty required to perform a task (item difficulty) and the respondent's level of ability to perform the task (person ability) on a linear scale. The results are expressed as a logit (natural logarithm of the odds ratio) unit. A respondent with a higher ability or an item with greater difficulty is expressed as a more negative logit value indicating a better score.

The outcome measures from Rasch modelling include category threshold order, item fit statistics, unidimensionality, measurement precision, targeting, and differential item functioning (DIF). Rasch analysis used v. 5.9.2 of the WINSTEPS software (Winsteps.com).

Secondary analyses used Welch 2-sample t tests to compare mean changes in Rasch person-measure logits and logMAR visual acuity between subgroups. Preoperative and postoperative logMAR visual acuity was compared using a paired t test. Significance was set at P < .05 (2-tailed). All subgroup analyses were performed using Python 3 (Google Colab, Google LLC). For subgroup analyses in Tables 3 and 4, P values represent statistical comparisons of the mean change before and after surgery between the 2 subgroups (eg, AMD vs non-AMD).

Table 3.

Subgroup Rasch-calibrated person-measure estimates and change before and after cataract surgery

Group	Pretest Mean (SD)	Posttest Mean (SD)	Mean change (SD)	P value
AMD
Yes	−1.74 (1.98)	−4.04 (2.49)	−2.3 (2.28)	.138
No	−1.31 (1.65)	−4.25 (2.05)	−2.94 (2.43)
Glaucoma
Yes	−1.28 (1.54)	−3.98 (1.62)	−2.70 (2.05)	.729
No	−1.37 (1.73)	−4.23 (2.17)	−2.86 (2.47)
DR
Yes	−0.23 (1.54)	−2.67 (1.09)	−2.44 (1.53)	.439
No	−1.41 (1.69)	−4.28 (2.12)	−2.87 (2.44)
Surgery eye
First-eye	−1.11 (1.65)	−4.36 (2.09)	−3.25 (2.40)	<.001a
Second-eye	−1.99 (1.67)	−4.04 (1.79)	−2.05 (1.90)
IOL
Monofocal	−1.30 (1.72)	−4.13 (2.17)	−2.83 (2.49)	.672
Premium	−1.68 (1.58)	−4.66 (1.75)	−2.98 (2.07)

AMD = age-related macular degeneration; DR = diabetic retinopathy

^aP value represents the statistical comparison of the mean change before and after surgery between the 2 subgroups

Table 4.

Preoperative and postoperative logMAR VA by subgroup

Group	Pretest Mean (SD)	Posttest Mean (SD)	Mean change (SD)	P value
AMD
Yes	0.46 (0.36)	0.24 (0.31)	−0.22 (0.25)	.885
No	0.40 (0.34)	0.17 (0.21)	−0.23 (0.33)
Glaucoma
Yes	0.42 (0.29)	0.14 (0.16)	−0.28 (0.24)	.309
No	0.41 (0.35)	0.18 (0.23)	−0.23 (0.32)
DR
Yes	0.33 (0.11)	0.21 (0.12)	−0.12 (0.17)	.081
No	0.41 (0.35)	0.18 (0.23)	−0.23 (0.32)
Surgery eye
First-eye	0.46 (0.37)	0.19 (0.25)	−0.26 (0.34)	.002a
Second-eye	0.30 (0.24)	0.15 (0.15)	−0.15 (0.22)
IOL
Monofocal	0.42 (0.36)	0.18 (0.24)	−0.24 (0.33)	.258
Premium	0.36 (0.24)	0.17 (0.15)	−0.19 (0.26)

AMD = age-related macular degeneration; DR = diabetic retinopathy

^aP value represents the statistical comparison of the mean change in logMAR VA before and after surgery between the 2 subgroups

RESULTS

A total of 257 Veterans were included in this study. Two hundred forty-one (93.8%) of the participants were male. Thirty-four (13.2%) participants had AMD, including 5 with neovascular AMD and the remaining 29 with dry AMD. Glaucoma was present in 23 patients (8.9%) and DR in 9 (3.5%). Most patients (70.4%) were undergoing their first-eye surgery (Table 1).

Table 1.

Baseline demographics and clinical characteristics

Characteristics	Total n = 257
Age (y), mean (SD)	74.6 (7.8)
Sex, n (%)
Female	16 (6.2)
Male	241 (93.8)
AMD, n (%)
No	223 (86.8)
Dry	29 (11.3)
Neovascular	5 (1.9)
Glaucoma, n (%)
No	234 (91.1)
Yes	23 (8.9)
Diabetic retinopathy, n (%)
No	248 (96.5)
Yes	9 (3.5)
First-eye surgery, n (%)	181 (70.4)
Second-eye surgery, n (%)	76 (29.6)
logMAR, mean (SD)	0.41 (0.34)

AMD = age-related macular degeneration

Rasch Analysis

Precision

Person separation was 2.25, and person reliability was 0.83, suggesting sufficient precision greater than 2.0 and 0.80, respectively. This indicates strong internal consistency and the ability to discriminate between patients with differing levels of visual difficulty.

Rating Scale

The Catquest-9SF uses a 4-point rating scale. All the 8 disability items and the satisfaction item exhibited ordered category thresholds, indicating proper functioning of response options (Figures 1 and 2).

Figure 1.

Category probability curves for the 8 Catquest-9SF disability items.

Figure 2.

Category probability curves for the Catquest-9SF satisfaction item.

Rasch fit statistics were generally satisfactory. All items had infit and outfit mean square values within acceptable limits (0.5 to 1.5), except for Item 6, which slightly exceeded both metrics. This suggests overall consistency in how patients interpreted and responded to the items. Rasch item calibrations and fit indices are summarized in Table 2.

Table 2.

Item fit characteristics

Question	Catquest-9SF item	Measure (SE)	Infit Mean Square	Outfit Mean Square
1	Global: Do you experience difficulty in daily life?	−0.83 (0.10)	0.62	0.62
2	Global: Are you satisfied or dissatisfied with your vision?	−0.76 (0.10)	0.64	0.64
3	Reading text in the newspaper	−0.37 (0.10)	1.03	0.82
4	Recognizing faces of people you meet	1.76 (0.14)	1.12	0.48
5	Seeing prices of goods when shopping	−0.24 (0.10)	0.94	0.89
6	Seeing to walk on uneven ground	1.92 (0.14)	1.62	1.56
7	Seeing to do needlework and handicraft	0.35 (0.11)	1.41	1.17
8	Reading text on television	−0.30 (0.10)	0.91	0.92
9	Seeing to carry out a preferred hobby	0.66 (0.11)	1.09	0.92

Dimensionality

Raw variance explained by measures was 65.4%, fitting the adequate criteria of greater than 60%. Unexplained variance in first contrast was Eigenvalue 1.6457, also fitting the adequate criteria of less than 2.0. Essential unidimensionality was 85.2%. This demonstrates that the items measure the intended function and that the summary scores are accurate.

Targeting Precision

The person-item map revealed a mean person ability of −1.37 logits, indicating that the items were somewhat easier than the average respondent ability, which is consistent and expected with postoperative visual improvements.

DIF

DIF analyses showed no DIF for sex. Some age-related DIF was observed across single-year age groups, but effect sizes were small, and no systematic bias affecting scale validity was identified.

Rasch-Calibrated Score Changes by Subgroup

The mean Rasch-based improvement for the full cohort was 2.85 logits. Patients with AMD (n = 34) had a slightly lower average improvement of 2.3 logits; 29 of 34 patients with AMD (85.3%) showed improvement. Among patients with glaucoma (n = 23), the mean improvement was 2.70 logits, with 21 of 23 (91.3%) demonstrating postoperative gains. Patients with diabetic retinopathy improved by 2.44 logits.

Participants undergoing first-eye surgery demonstrated greater improvement (3.25 logits) than those undergoing second-eye surgery (2.05 logits, P < .001). Monofocal IOL recipients improved by 2.83 logits, and premium IOL recipients by 2.98 logits, with no significant difference between lens types. No other subgroup comparisons (eg, AMD vs non-AMD, glaucoma vs nonglaucoma, and DR vs non-DR) reached statistical significance (Table 3).

Visual Acuity Outcomes

As a secondary outcome, visual acuity was assessed after cataract surgery overall and in the setting of comorbidities and surgical status. logMAR visual acuity significantly improved from 0.41 ± 0.34 to 0.18 ± 0.22 (mean change −0.23; P < .001) (Table 4).

Subgroup comparisons did not reveal statistically significant differences in visual acuity by comorbidities (AMD, glaucoma, and DR) or IOL type. However, patients undergoing first-eye surgery experienced a significantly greater improvement in logMAR VA compared with those undergoing fellow-eye surgery (−0.26 vs −0.15; P = .002).

DISCUSSION

PROMs have become essential tools throughout medicine and within ophthalmology to understand surgical benefits beyond traditional measures.^12–15 The Catquest-9SF specifically has been validated in multiple international settings and endorsed by the International Consortium for Health Outcomes Measurement for cataract care benchmarking.^8,9,16–21 To the authors' knowledge, this is the first study to use the Catquest-9SF with a U.S. population, specifically a VA cohort. This study's primary objective was to assess the validity of the Catquest-9SF in a U.S. Veteran population. Secondary objectives were to assess to what extent patients' functioning and visual acuity improved after cataract surgery and to evaluate potential effects of the type of IOL used and comorbidities.

In our population, the Catquest-9SF performed well under Rasch modeling. Item fit statistics fell largely within acceptable ranges, with only 1 item (“seeing to walk on uneven ground”) slightly exceeding ideal infit and outfit thresholds. This question may have been inadequate in the United States compared with other settings for several reasons. First, the prevalence of uneven walking surfaces such as cobblestone streets is generally higher in other countries, potentially making this task more salient abroad. Second, data suggest that U.S. residents engage in less daily walking than those in other countries, which may reduce the perceived importance of this activity.²²

Overall, this Questionnaire demonstrated internal consistency, clear unidimensionality, and appropriate item difficulty distribution, suggesting that the Catquest-9SF can be adequately used in a U.S. Veteran population. Interestingly, in another English version of this study performed in Canada, the “difficulty with vision” question was misfit, whereas it fits well in our cohort.²³ These variations highlight how cultural, linguistic, and healthcare system differences can influence the interpretation and performance of PROM items across populations.

Examining our secondary objectives, it was evident that cataract surgery led to an increase in patient-reported functioning and their visual acuity. This notion has been well documented in the literature with up to 90% of patients undergoing first-eye cataract surgery noting to have improvement in functional status and satisfaction with vision.^2,24–27 In our academic setting with ophthalmology residents often acting as a primary surgeon, this trend followed the prior literature of subjective and objective benefits after cataract surgery.

Several studies have demonstrated that ocular comorbidities are associated with less favorable patient-reported outcomes and objective measures after cataract surgery.^28–30 Our subgroup analysis sought to determine whether patients with comorbid conditions including DR, AMD, and glaucoma exhibited different outcomes compared with those without these conditions. Rasch analysis indicated a reduced magnitude of change among patients with comorbidities. Patients with AMD demonstrated the smallest improvement in Rasch person-measure estimates, while those with glaucoma showed the largest numerical improvement. However, these subgroup differences were not statistically significant. Furthermore, the improvement in visual acuity among these groups was on par with the improvement seen in those without any comorbidities.

Furthermore, although previous studies have reported that premium IOLs improve patient-reported spectacle independence and near/intermediate vision, our data showed no significant difference in outcomes, either with visual acuity or PROMs, between monofocal and premium IOL recipients.^31,32 In addition, although our study did show a statistically significant improvement in visual acuity mean change in first-eye surgery patients vs fellow eye, this is likely due to the institutional process at the Hines VA where surgery is typically performed on the eye with worse preoperative visual acuity first. These findings can help physicians have a more robust and meaningful discussion around informed consent, with consideration for specific comorbidities and IOL choice.^22,23

There are multiple other PROMs used to measure cataract surgery, yet the Catquest-9SF offers several advantages. First, it is shorter and thus quicker to administer than other counterparts including VF-14 and National Eye Institute Visual Functioning Questionnaire-25. Second, when compared with 16 other PROMs, it showed the greatest effect size, demonstrating robust responsiveness.³³ Third, the Rasch scaling allows interval level measurements which can help track changes both overall and item-specific changes. Finally, it has been shown to fit relevant daily functioning in the U.S. population, which can help provide an overall assessment of practical improvement after surgery.

This study had several limitations. First, although it is the first to our knowledge to study a U.S. population, the investigation of a solely Veteran population limits generalizability to broader civilian populations. Second, the cohort was predominantly male, reflecting the U.S. Veteran demographic, which further restricts applicability to more diverse populations. Third, the single-center design also introduces potential bias related to institutional practices and surgeon-specific variations. Finally, although the overall sample size was adequate for Rasch calibration, the subgroup analyses were exploratory and not powered to detect statistically significant differences.

Future research should include a larger, more diverse U.S. population to reconfirm our results and validate generalizability across sex, race, and civilian populations and evaluate impact of their comorbidities. In addition, further studies may be used to test whether a more appropriately worded question for walking on uneven surfaces fits the model better in an American population. Finally, future studies may explore how this Questionnaire can be used to other ocular procedures.

In conclusion, the Catquest-9SF questionnaire demonstrated strong psychometric validity in this U.S. Veteran population, supporting its utility for large-scale application within VA healthcare settings and potentially all settings in the United States. In addition, it displayed improvements in patient's overall visual functioning after cataract surgery, as well as in a variety of every day settings. Specifically, although the improvement in visual acuity was statistically greater in first-eye surgeries, there were no significant differences by comorbidities or IOL type. This allows physicians to give patients more tailored and meaningful expectations after cataract surgery based on their individual situation. Therefore, the Catquest-9SF questionnaire with demonstrated psychometric properties is a unique tool, which can be used to measure outcomes, improve patient education, set expectations, and inform shared decision-making.

WHAT WAS KNOWN

• Cataract surgery is one of the most frequently performed surgeries in the world and has been shown to lead to improved outcomes in functional vision and acuity.

• Patient-reported outcome measures (PROMs) can provide critical insight in understanding qualitative changes in patients' lives after cataract surgery.

• The Catquest-9SF questionnaire has shown to be an internationally validated tool that assesses vision-related quality of life after cataract surgery in a responsive manner and has not been used in a U.S. Veterans population.

WHAT THIS PAPER ADDS

• This is the first report, to the authors' knowledge, of the use of Catquest-9SF as a PROM tool to investigate cataract surgery outcomes in the United States and specifically among U.S. Veterans.

• This study supports the utility of the Catquest-9SF questionnaire in large-scale Veteran healthcare settings and potentially among the broader U.S. population.

• This study emphasizes on evaluating health intervention efficacies from the patient's perspective to gauge qualitative outcomes and better inform patient expectations postintervention.