Introduction
The assessment of patient-reported outcomes (PROMs) has become a cornerstone of modern ophthalmology, particularly in evaluating the success of cataract interventions. Among the various tools available, the Catquest-9SF Patient Outcomes Questionnaire stands out as a premier, 9-item short-form instrument specifically designed to measure visual disability. Originally, Mats Lundström and Konrad Pesudovs developed this instrument in 2009 as a streamlined version of the original 19-item Catquest. Since its publication in the Journal of Cataract & Refractive Surgery, the Catquest-9SF has garnered over 300 citations in scientific literature, reflecting its widespread acceptance in the academic community. Furthermore, researchers favor it because it utilizes Rasch analysis to provide interval-level measurement, ensuring that the data collected is statistically robust and clinically meaningful.
This article explores the Catquest-9SF, highlighting its role in bridging the gap between clinical data and patient quality of life. It provides clinicians and researchers with essential insights into its structure, scoring, and global validation.
Key Features of the Catquest-9SF Patient Outcomes Questionnaire (CatQuest-9SF)
Purpose and Use
The Catquest-9SF is engineered to provide a comprehensive evaluation of how cataracts interfere with a patient’s lifestyle and functional independence. By utilizing this instrument, researchers and clinicians can systematically capture specific performance metrics across various daily activities:
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- Reading abilities: Assessing difficulties with fine-print tasks such as reading newspapers or labels.
- Recognition tasks: Evaluating the patient’s capacity to identify faces or familiar features at a distance.
- Mobility and Safety: Measuring challenges related to depth perception and navigation, such as seeing stairs or uneven surfaces.
- Overall Satisfaction: Gauging the subjective contentment with current vision and the perceived necessity for surgical intervention.
Target Population
While cataracts are most prevalent in older populations, researchers have validated the Catquest-9SF for adults of all ages. Specifically, clinicians utilize it for:
- Young and Middle-Aged Adults (18–44 years)
- Older Adults (45–64 years)
- Seniors (65+ years)
Clinicians designed the tool for cataract patients undergoing surgical evaluation or post-operative follow-up.
Structure
Structurally, the Catquest-9SF is a 9-item questionnaire that covers the essential facets of visual function. These items are categorized into the following sub-domains:
- Perceived Visual Difficulties in Daily Life: Assessing challenges with specific tasks.
- Activity Limitation: How vision restricts mobility or hobbies.
- Satisfaction with Vision: The patient’s subjective contentment with their sight.
- Global Index of Visual Function: An overall measure of visual capability.
In particular, the questions specifically target difficulties with activities such as reading a newspaper, recognizing faces, seeing stairs, and the perceived need for surgery.
Scoring Method
Regarding the scoring, the Catquest-9SF is sophisticated yet flexible. It primarily employs a Rasch-analysis scoring method, which converts raw ordinal responses into a logit-based interval scale. This approach is superior for scientific research as it allows for more accurate statistical comparisons. However, for a quick clinical estimate, clinicians can use a simplified raw score calculation (summing item responses).
The tool scores items on two distinct 5-point Likert scales:
- Difficulty Scale: 1 (Very great difficulty) to 4 (No difficulty), with a 5 option for “Cannot decide.”
- Satisfaction Scale: 1 (Very dissatisfied) to 4 (Very satisfied), with a 5 option for “Cannot decide.”
Administration Format
Practically, efficiency is a hallmark of the Catquest-9SF. Moreover, it is a self-administered tool that typically requires less than 5 minutes to complete. Additionally, it can be delivered through various formats:
- Paper-based forms
- Digital (Online) platforms
- In-person interviews
- Phone or Video calls
Application of the Catquest-9SF Patient Outcomes Questionnaire (CatQuest-9SF)
The clinical utility of the Catquest-9SF extends across several domains of ophthalmic care:
- Screening: Identifying patients whose visual disability justifies surgical intervention.
- Monitoring: Comparing pre-operative and post-operative scores to quantify surgical success.
- Treatment Planning: Helping surgeons understand which daily activities are most hindered by the patient’s cataract.
- Research Endpoint: Serving as a primary or secondary outcome measure in clinical trials comparing different intraocular lenses (IOLs) or surgical techniques.
Languages and availability
To facilitate international research, the Catquest-9SF has been translated and validated in numerous languages, including:
- English
- Mandarin Chinese
- Spanish
- French
- German
- And others
Moreover, the instrument is Open Access and generally free for use, though some digital platforms or specific publisher-controlled versions may have restricted access.
Reliability and Validity
The Catquest-9SF is recognized as a highly reliable and valid instrument for assessing patient-reported visual outcomes. Its psychometric soundness is supported by a high Cronbach’s alpha (typically > 0.90), indicating excellent internal consistency. Furthermore, the 9SF version has demonstrated exceptional Rasch-based fit statistics and strong construct validity across various global populations. Below are the key validation studies supporting its use:
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- The original validation Study link
- Systematic review of Catquest-9SF validation in various populations. Study Link
- Validation of the Catquest-9SF in a Canadian population. Study Link
- Translation and validation of the Italian Catquest-9SF. Study Link
- Validation of the Spanish version for monofocal and trifocal IOL patients. Study Link
- Validity of the French version and electronic notepad implementation. Study Link
- Validation of the Catquest-9SF in a Chinese cataract population. Study Link
Limitations and Considerations
Despite its strengths, the Catquest-9SF has a few limitations:
- Self-report: Respondents may be influenced by social desirability bias or personal interpretation.
- Narrow Focus: It specifically targets cataract-related visual disability and may not capture the full spectrum of other ocular comorbidities.
- Age Restrictions: While validated for adults, it is not designed or suitable for pediatric populations.
Other Versions And Related Questionnaires
Researchers may also consider the original CatQuest (19-item version) if a more exhaustive assessment is required. Additionally, the Catquest-9SF is often used alongside or compared to other visual function tools such as:
- VF-14 (Visual Function Index)
- NEI VFQ-25 (National Eye Institute Visual Function Questionnaire)
- IVI (Impact of Vision Impairment)
Additional Resources
- The Original Validation : Study link
- You can access the questionnaire as a PDF through this link: Direct PDF Access
- For inquiries, contact Mats Lundström, the first author of the questionnaire: mats.lundstrom@karlskrona.mail.telia.com
- For additional resources, consult the publisher (Elsevier/ASCRS): Journal Home
Frequently Asked Questions (FAQ)
- Who can use the Catquest-9SF?
Clinicians, researchers, and healthcare providers use the Catquest-9SF for adult patients (18+) who are candidates for or have undergone cataract surgery. - How long does it take to complete the Catquest-9SF?
Patients typically take less than 5 minutes to complete the questionnaire, making it one of the most efficient PROMs available for busy clinics. - How is the Catquest-9SF administered?
Healthcare teams can administer it via paper, digital platforms, or through interviews (in-person or via phone/video). - Is there any cost to using the Catquest-9SF?
The Catquest-9SF is generally free to use. However, users should check specific publisher requirements if utilizing it within commercial or heavily funded academic projects.
- Who can use the Catquest-9SF?
A Word from ResRef about the Catquest-9SF Patient Outcomes Questionnaire (CatQuest-9SF)
The Catquest-9SF is a gold-standard, patient-centric tool in ophthalmic surgery. Its Rasch-scaled design provides robust, interval-level measurement, making it superior to many raw-score instruments. Its 5-minute administration time makes it highly feasible for busy clinical settings, ensuring that the patient’s voice is systematically integrated into outcome assessment. Consequently, it remains a premier example of a well-constructed, disease-specific Patient Reported Outcome Measure.
References
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- Lundström, M., & Pesudovs, K. (2009). Catquest-9SF patient outcomes questionnaire: Nine-item short-form Rasch-scaled revision of the Catquest questionnaire. Journal of Cataract & Refractive Surgery, 35(3), 504-513. link
- Kabanovski, A., Hatch, W., Chaudhary, V., El-Defrawy, S., Reid, R., & Ahmed, I. I. K. (2020). Validation and application of Catquest-9SF in various populations: A systematic review. Survey of Ophthalmology, 65(3), 348-360. link
- Schlenker, M. B., Minotti, S. C., Kabanovski, A., Lim, M., D’Silva, C., Ma, J., Reid, R., & Ahmed, I. I. K. (2020). Catquest-9SF questionnaire and eCAPS: Validation in a Canadian population. PLoS ONE, 15(9), e0237788. link
- Skiadaresi, E., Ravalico, G., Polizzi, S., Lundström, M., Gonzalez-Andrades, M., & McAlinden, C. (2016). The Italian Catquest-9SF cataract questionnaire: translation, validation and application. Eye and Vision, 3(1), 1-8. link
- Lundström, M., Llovet, F., Llovet, A., Martinez del Pozo, M., Mompean, B., Gonzalez, J. V., & Pesudovs, K. (2016). Validation of the Spanish Catquest-9SF in patients with a monofocal or trifocal intraocular lens. Journal of Cataract & Refractive Surgery, 42(12), 1791-1796. link
- Katz, G., Rouquette, A., Lignereux, F., Mourgues, T., Weber, M., & Lundström, M. (2021). Validation and application of the French version of the Catquest-9SF cataract questionnaire. Eye and Vision, 8(1), 1-11. link
- Lin, X., Li, M., Wang, M., Zuo, Y., Zhu, S., Zheng, Y., Lin, X., Yu, M., & Lamoureux, E. L. (2014). Validation of Catquest-9SF Questionnaire in a Chinese Cataract Population. PLoS ONE, 9(8), e103860. link
