Decision trees for indication of cataract surgery based on changes in visual acuity.

OBJECTIVE: To develop decision trees based on prospectively collected data for determining the appropriateness of cataract extraction. DESIGN: Prospective observational cohort study. PARTICIPANTS: Consecutive patients with a diagnosis of cataract who are on waiting lists to undergo cataract extraction by phacoemulsification. METHODS: Patients were randomly assigned to 1 of 2 independent cohorts: The derivation cohort included 3691 patients, and the validation cohort included 2416 patients. Sociodemographic and clinical data, including visual acuity (VA) and the Visual Function Index 14 (VF-14), were collected before and after cataract extraction. Univariate and multivariate linear regression, and regression trees analysis were performed in the derivation cohort. Decision trees obtained in the derivation cohort were validated in the validation cohort. Final results were divided into appropriate or inappropriate indications and compared with a previously established benchmark of desirable VA and VF-14 gain in relation to preintervention VA classes. MAIN OUTCOME MEASURES: Preintervention VA and changes 6 weeks after the intervention. RESULTS: Among patients with simple cataract, predictors of significant improvement in VA after cataract extraction were preintervention VA and negative surgical complexity. Among patients with cataract and other ocular comorbidity, preintervention visual function and expected postintervention VA also predicted change in VA. When compared with a benchmark based on the minimal clinically important difference in VA after cataract extraction, sensitivity for the decision trees was 83% for both diagnostic groups and specificities ranged from 36.2 to 54.8. CONCLUSIONS: A simple decision tree based on changes in VA can help identify appropriate patients for cataract extraction and be used to evaluate clinical practice or for quality control.

Can an appropriateness evaluation tool be used to prioritize patients on a waiting list for cataract extraction?

OBJECTIVES: To determine whether a system originally developed to ascertain the appropriateness of cataract intervention may also be used to prioritize patients on cataract extraction waiting lists. METHODS: The IRYSS-appropriateness of indication for cataract surgery tool and the IRYSS-Cataract Priority Score were applied to a sample of 5448 patients consecutively placed on waiting lists for cataract surgery. Clinical data were gathered by ophthalmologists, and patients self-completed the Visual Function Index-14. The general linear model (GLM) was used to assign scores to the categories of the appropriateness and priority criteria. The relationship between both systems was evaluated by correlating scores. To assess the validity of the new appropriateness and priority scores, correlations with visual acuity (VA) and visual function were calculated. RESULTS: The GLM method generated highly similar scores for both appropriateness and prioritization systems. The correlation between scores was very strong (r=0.96). The appropriateness scoring system correlated 0.29 with VA and 0.21 with gain in visual function. The priority system correlated -0.54 with VA and -0.28 with preintervention visual function. CONCLUSIONS: The new appropriateness scoring system strongly correlates with the priority scoring system. This easy-to-use appropriateness rating could serve as a tool for simultaneously assessing the appropriateness of cataract surgery and assigning priority.

Appropriateness of phacoemulsification in Spain.

OBJECTIVE: To evaluate the appropriateness of phacoemulsification procedures performed in four Spanish regions, applying criteria developed by means of RAND/UCLA methodology. DESIGN: Prospective observational study. SETTING: Seventeen public teaching hospitals in four regions of Spain. PARTICIPANTS: Patients on waiting list to undergo cataract extraction by phacoemulsification. INTERVENTION: Cataract surgery by phacoemulsification. MAIN OUTCOME MEASURE: Level of appropriateness of each intervention, according to criteria developed by means of the RAND/UCLA appropriateness methodology. RESULTS: Among the 5442 analysed patients the indication of phacoemulsification was appropriate in 69.6%, inappropriate in 7.3% and uncertain in 23.0%. Presence of ocular comorbidity, lack of cataract-induced visual function limitation, anticipated postoperative visual acuity of <0.5, preoperative visual acuity of >0.1 and high surgical complexity were associated with inappropriateness. CONCLUSIONS: Some clinical characteristics, when present, make it especially important to obtain a careful assessment of the risks and benefits of surgery. Consideration of these characteristics may improve the appropriateness of phacoemulsification.

Validation of priority criteria for cataract extraction.

RATIONALE, AIMS AND OBJECTIVES: Given the increasing prevalence of cataract and demand for cataract extraction surgery, patients must often wait to undergo this procedure. We validated a previously developed priority scoring system in terms of clinical variables, pre-intervention health status, appropriateness of surgery and gain in visual acuity (VA) and health-related quality of life (HRQoL). METHODS: Explicit prioritization criteria for cataract extraction created by a variation of the Research and Development (RAND) and University of California Los Angeles appropriateness methodology were retrospectively applied to a prospective cohort of 5257 patients on waiting lists to undergo cataract by phacoemulsification at 17 hospitals in Spain. Demographic data, clinical data and data related to surgical technique were collected by trained ophthalmologists. Patients were evaluated by their ophthalmologist before the intervention and 6 weeks afterward. They also completed, by mail, the Visual Function Index (VF-14) before the intervention and 3 months afterward. RESULTS: High-priority patients experienced greater improvement in VA and HRQoL than those classified as intermediate or low-priority (P < 0.0001), even after adjusting by VA and the VF-14 score at baseline. The time to intervention was the same for high-priority patients as it was for intermediate and low-priority patients. CONCLUSIONS: The priority score we developed identified patients most likely to experience the greatest improvements from cataract extraction. Use of this tool could provide a fairer and more rational way to prioritize patients for cataract extraction.

Responsiveness and clinically important differences for the VF-14 index, SF-36, and visual acuity in patients undergoing cataract surgery.

OBJECTIVE: To assess visual acuity (VA) and 2 questionnaires of health-related quality of life--the Visual Function 14 (VF-14) index and the Medical Outcomes Study Short Form 36 Health Survey (SF-36)--as instruments for capturing clinically important changes after cataract surgery. DESIGN: Prospective, observational study. PARTICIPANTS: Four thousand three hundred fifty-six consecutive patients attending ophthalmologic clinics in 17 hospitals in preparation for cataract surgery were recruited. METHODS: Clinical data were collected in the visit before the intervention and 6 weeks after surgery by ophthalmologists. Patients completed the questionnaires before surgery and 3 months after surgery. MAIN OUTCOME MEASURES: The VF-14 and SF-36 questionnaire results obtained before surgery and 3 months after the procedure and VA before the procedure and 6 weeks afterward. RESULTS: Positive mean changes in VA (+0.47) and VF-14 results (+24.03) indicated significant improvements after cataract surgery that were not reflected in changes in SF-36 domains (from 1.86 to 5.62). Responsiveness parameters demonstrated large changes in VA and VF-14 scores but not in SF-36 domains. The minimal clinically important differences (MCID) after surgery were 0.41 for VA and 15.57 for VF-14 results; the minimal detectable change (MDC) for VF-14 was 10.81. CONCLUSIONS: Visual acuity and VF-14 scores, but not SF-36 scores, are appropriate instruments for capturing clinically important changes after cataract surgery. The MCID and MDC values obtained herein, although not absolute thresholds, may aid in the interpretation of changes in VA and VF-14 scores.

[Singularization processes: a proposal for continuity between clinical activity and health policy objectives]. / Singularizar procesos: una propuesta de continuidad entre la actividad clínica y los objetivos de salud de las políticas sanitarias.

BACKGROUNDS AND OBJECTIVES: In 1996 the Gipuzkoa Territorial Health Agency (Basque Country, Spain) created the Health Plan Service. The aim was to transform the health objectives prioritized by the Health Department into intervention strategies to be incorporated into the local contract services. PROCESS AND RESULTS: One of the procedures the service uses for this purpose, known as <>, involves selecting a process linked to a prioritized health problem, and analyzing and reconstructing it so that the related activity, expected results, financial costs and its impact on the population's health can be identified. After this process the service provides the Territorial Health Agency, which is responsible for service purchase for the public and private sectors, with information about contract conditions for the process reviewed. Annual assessment of contract services monitors the extent to which the agreements made have been carried out and their consequences on the population's health. The present article deals with the process through which this <> is carried out.

Singularizar procesos: una propuesta de continuidad entre la actividad clínica y los objetivos de salud de las políticas sanitarias / Singularization processes: a proposal for continuity between clinical activity and health policy objectives

Antecedentes y objetivos: La Dirección Territorial de Sanidad de Gipuzkoa creó en 1996 el servicio del Plan de Salud con la finalidad de transformar los objetivos de salud priorizados por el Departamento de Sanidad en estrategias de intervención a incorporar a los contratos programa. Proceso y resultados: el procedimiento que el servicio está utilizando para cumplir este objetivo se denomina singularización y consiste en seleccionar un proceso vinculado a un problema de salud prioritario, analizarlo y reconstruirlo de forma que se conozca la actividad relacionada con él, los resultados, el coste económico y su impacto en la salud de la población. El procedimiento permite a la Dirección Territorial de Sanidad, responsable de la compra de servicios al sector público y privado, disponer de información sobre las condiciones de contratación para el proceso revisado. La evaluación anual de los Contratos programa y Conciertos controla el grado de consecución de los pactos realizados y de sus consecuencias sobre la salud de la población. El artículo que se presenta recoge la forma en la que se realiza esta singularización

Backgrounds and objectives: In 1996 the Gipuzkoa Territorial Health Agency (Basque Country, Spain) created the Health Plan Service. The aim was to transform the health objectives prioritized by the Health Department into intervention strategies to be incorporated into the local contract services. Process and results: One of the procedures the service uses for this purpose, known as «singularization», involves selecting a process linked to a prioritized health problem, and analyzing and reconstructing it so that the related activity, expected results, financial costs and its impact on the population's health can be identified. After this process the service provides the Territorial Health Agency, which is responsible for service purchase for the public and private sectors, with information about contract conditions for the process reviewed. Annual assessment of contract services monitors the extent to which the agreements made have been carried out and their consequences on the population's health. The present article deals with the process through which this «singularization» is carried out