School of Public Health, The University of Hong Kong, Hong Kong.
Ophthalmology. 2013 Jun;120(6):1247-53. doi: 10.1016/j.ophtha.2012.11.024. Epub 2013 Apr 12.
To examine whether the inverse care law operates in a screening program for diabetic retinopathy (DR) based on fee for service in Hong Kong.
Randomized controlled trial.
All those with type 1 or 2 diabetes from 2 clinics were recruited.
Diabetic retinopathy screening with a small copayment versus free access in a publicly funded family medicine service.
Uptake of screening and severity of DR detected. Association between these outcome variables and independent variables were determined using multivariate logistic regression models and reported as odds ratios (ORs).
After randomization, 1387 subjects in the free group and 1379 subjects in the pay group were eligible for screening, and 94.9% (1316/1387) and 92.6% (1277/1379), respectively, agreed to participate in the study. The offer of screening was accepted by 94.8% (1247/1316) in the free group and 91.2% (1164/1277) in the pay group, and the final uptake ratios were 88.5% (1165/1316) and 82.4% (1052/1277), respectively (Pearson chi = 19.74, P<0.001). Being in the pay group was associated with a lower uptake of screening than being in the free group (OR, 0.59; confidence interval [CI], 0.47-0.74) and a lower detection rate of DR (OR, 0.73; CI, 0.60-0.90) after adjustment for potential confounding factors. Subjects with higher socioeconomic status were more likely to attend screening and had a lower prevalence of DR detected.
The inverse care law seems to operate in a preventive intervention when a relatively small copayment is applied. There is a case for making effective preventive services free of charge.
FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
检验在香港基于按服务收费的糖尿病视网膜病变（DR）筛查计划中是否存在反向护理定律。
随机对照试验。
从 2 家诊所招募所有 1 型或 2 型糖尿病患者。
DR 筛查，小额度自付与公共资助家庭医学服务免费。
筛查参与率和 DR 严重程度。使用多变量逻辑回归模型确定这些结果变量与自变量之间的关系，并报告为优势比（OR）。
随机分组后，免费组有 1387 名符合筛查条件的受试者，付费组有 1379 名符合筛查条件的受试者，分别有 94.9%（1316/1387）和 92.6%（1277/1379）同意参加研究。免费组的筛查接受率为 94.8%（1247/1316），付费组为 91.2%（1164/1277），最终参与率分别为 88.5%（1165/1316）和 82.4%（1052/1277）（皮尔逊卡方=19.74，P<0.001）。与免费组相比，付费组的筛查参与率较低（OR，0.59；95%置信区间[CI]，0.47-0.74），DR 检出率也较低（OR，0.73；95%CI，0.60-0.90），调整潜在混杂因素后结果仍有统计学意义。社会经济地位较高的受试者更有可能接受筛查，且检出的 DR 患病率较低。
当收取较小的自付额时，反向护理定律似乎适用于预防性干预。有理由使有效的预防服务免费。
作者没有讨论的材料有任何专有的或商业的利益。
