Reliability and validity of the Cancer Health Literacy Test - Chinese versions: CHLT-30-Chinese and CHLT-6-Chinese.

Aims The Cancer Health Literacy - 30 (CHLT-30) and Cancer Health Literacy - 6 (CHLT-6) are widely used instruments to measure cancer health literacy and to identify individuals with limited cancer health literacy, respectively. This study evaluated the psychometric performance of both instruments in Chinese cancer patient population. Methods The back-translation method was used in cross-cultural adaptation. Chinese versions, labeled as CHLT-30-Chinese and CHLT-6-Chinese, were administered to a diverse cross-sectional sample of 602 cancer patients. Of these, 30 patients retook the instruments over a 2-week interval to estimate test-retest reliability. Classical and modern psychometric methods were used to estimate the item and test properties. Results Model fit statistics confirmed the original measurement structures of CHLT-30-Chinese (one-factor model) and CHLT-6-Chinese (latent class model with limited and adequate cancer health literacy classes) providing construct validity evidence. The CHLT-30-Chinese showed high internal consistency (Cronbach's α = 0.83; McDonald's Ω = 0.93) and 2-week test-retest reliability (r = 0.78). The CHLT-6-Chinese separated limited and adequate cancer health literacy classes well (entropy = 0.77) with the estimated prevalence rates of 19% and 81%, respectively. The CHLT-6-Chinese was highly precise in assigning cancer patients into two categories: limited and adequate cancer health literacy classes with probability of 0.95 and 0.90, respectively. Invariant measurement properties of both instruments were supported between male and female patients as well as patients with and without high school diploma. Conclusions The findings support the psychometric properties of the CHLT-30-Chinese for measuring cancer health literacy as a continuous trait and CHLT-6-Chinese for identifying patients with limited cancer health literacy with high precision. The two tools are recommended for use in both daily practice and clinical trials.