Alonso J, Espallargues M, Andersen T F, Cassard S D, Dunn E, Bernth-Petersen P, Norregaard J C, Black C, Steinberg E P, Anderson G F
Health Services Research Unit. Institut Municipal d'Investigació Mèdica (IMIM), Barcelona, Spain.
Ophthalmology. 1997 May;104(5):799-807. doi: 10.1016/s0161-6420(97)30230-9.
There is increased recognition that a rigorous approach to functional assessment should complement the assessment of clinical status. The authors compare the reliability, validity, and responsiveness to clinical change of a visual function index (VF-14) in non-U.S. and in U.S. patients with cataracts.
An observational longitudinal study was performed.
One thousand four hundred seven first eye cataract surgery patients were recruited in four international sites: Manitoba (Canada), Denmark, Barcelona (Spain), and the United States.
Patients were evaluated before cataract surgery and at a 4-month postoperative follow-up visit. Patients completed the preoperative interview and the clinical examination (766 in the United States, 152 in Manitoba, 291 in Denmark, and 198 in Barcelona), and 91.3% of those (1284) also completed the 4-month postoperative follow-up interview and were evaluated postoperatively by an ophthalmologist.
The authors used the following measures: the visual function index (VF-14), the Sickness Impact Profile (SIP), global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity (VA) in each eye.
The VF-14 showed a high internal consistency reliability level in all sites (Cronbach's alpha coefficients > or = 0.84). Correlation of preoperative visual function index scores with the Vision-Related SIP was strong (r = -0.68 in non-U.S. and r = -0.57 in U.S. patients) and with VA in the eye with better vision was moderate (r = 0.40 and r = 0.27, respectively), the pattern of relationships being very similar among U.S. and non-U.S. patients. In patients with only first-eye surgery who reported that their initial trouble with vision had improved, the amount of change in visual function as assessed by the VF-14 (effect size) was large (1.01 for the non-U.S. patients and 1.17 for the U.S. patients).
The non-U.S. versions of the visual function index (VF-14) analyzed are as reliable, valid, and responsive to clinical change as the original U.S. version. These versions are appropriate for international studies of cataract patients outcomes and possibly in routine clinical practice.
人们越来越认识到，严格的功能评估方法应补充临床状况评估。作者比较了非美国和美国白内障患者视觉功能指数（VF-14）的可靠性、有效性以及对临床变化的反应性。
进行了一项观察性纵向研究。
在四个国际地点招募了1407例首次接受白内障手术的患者：加拿大马尼托巴省、丹麦、西班牙巴塞罗那和美国。
在白内障手术前和术后4个月的随访中对患者进行评估。患者完成术前访谈和临床检查（美国766例，马尼托巴省152例，丹麦291例，巴塞罗那198例），其中91.3%（1284例）还完成了术后4个月的随访访谈，并由眼科医生进行术后评估。
作者采用了以下指标：视觉功能指数（VF-14）、疾病影响量表（SIP）、患者视力问题和满意度的总体指标以及每只眼睛的最佳矫正视力（VA）。
VF-14在所有地点均显示出较高的内部一致性可靠性水平（克朗巴哈系数≥0.84）。术前视觉功能指数评分与视力相关SIP的相关性很强（非美国患者r = -0.68，美国患者r = -0.57），与视力较好眼睛的VA相关性中等（分别为r = 0.40和r = 0.27），美国和非美国患者之间的关系模式非常相似。在仅接受第一眼手术且报告其最初视力问题有所改善的患者中，VF-14评估的视觉功能变化量（效应量）很大（非美国患者为1.01，美国患者为1.17）。
所分析的非美国版视觉功能指数（VF-14）与原始美国版一样可靠、有效且对临床变化有反应。这些版本适用于白内障患者结局的国际研究，也可能适用于常规临床实践。
