# Validation of the Chinese version of the financial toxicity scale in patients with wet age-related macular degeneration

## TL;DR

This study validated the Chinese version of the COST scale for measuring financial toxicity in patients with wet age-related macular degeneration.

## Contribution

The study confirms the Chinese version of the COST scale is valid and reliable for assessing financial toxicity in wAMD patients.

## Key findings

- The Chinese COST scale showed strong item-total correlations and high internal consistency (Cronbach’s α of 0.876).
- Factor analysis identified three factors with a cumulative variance contribution rate of 67.739%.
- Content validity indices were high, with an S-CVI of 0.974.

## Abstract

to confirm the validity of the Comprehensive Score for Financial Toxicity (COST) Scale in Chinese patients with wet age-related macular degeneration.

A tertiary hospital in Wuxi’s ophthalmology outpatient clinic treated 217 patients with wet age-related macular degeneration (wAMD) were chosen using the convenience sample approach for a questionnaire survey between October 2023 and February 2024. The Chinese version of the COST and general patient information were included in the survey. Critical ratio analysis and correlation analysis were used to examine the items on the scale. The structural validity of the scale was evaluated using factor analysis, the reliability of the scale was evaluated using Cronbach′s α coefficient and retest reliability, and the content validity of the scale was evaluated using the Content Validity Index (CVI).

The item analysis results demonstrated that high and low subgroups could be identified using The COST scale’s Chinese translation (P < 0.01).; A linear positive correlation was observed between the scores of each item and the scale’s overall scores (r values of 0.243 ~ 0.878, P < 0.01), and the scores of factor 1, factor 2, and factor 3 showed a linear positive correlation with the total scores of the scale (accordingly, r values were 0.974, 0.505, and 0.300; P < 0.01). and the scores of each item were linearly and positively correlated with the scores of the common factors to which they belonged (r values of 0.642 to 1.000, P < 0.01). Content validity showed that the I-CVI of each item was 0.857 ~ 1.00, and the S-CVI was 0.974. Three metrics in all, with a cumulative variance contribution rate of 67.739%, were obtained through exploratory factor analysis. Each item’s loading on the corresponding dimensions varied from 0.638 to 0.954. The Cronbach’s α coefficient for the entire scale was 0.876(95% CI: 0.85–0.899). The reliability of the retest was 0.970 (95% CI: 0.936–0.990).

The Chinese version of the COST scale shows potential applicability pending further validation.