Impact of Limited E-Health Literacy on the Overall Survival of Patients With Cancer

Abstract

Purpose: Digitalization of the health care system is transforming cancer patient care. Although many studies have investigated the determinants of a limited digital health literacy, the association between frailty factors and overall survival (OS) of these patients has never been assessed.

Methods: A retrospective noninterventional study included 15,244 adult patients with cancer diagnosed between January 1, 2015, and December 31, 2017, and treated at the Centre Léon Bérard. Limited e-health literacy was defined as the absence of an e-mail address in the electronic patient record. An Inverse Probability of Treatment-Weighted Kaplan-Meier estimate and a multivariate Cox proportional hazards model including interaction terms were used to adjust for confounding on measured covariates.

Results: In total, 15,244 adults with cancer were included: 55% women, with a median age of 62 years (19-103), and 35.5% had a metastatic disease. More than half (n = 8,771, 57.5%) had entered their e-mail address in their electronic patient record, and 4,020 (26.4%) opened their own patient portal. The median follow-up was 3.6 years (range: 0-6.8). Inverse Probability of Treatment-weighted Kaplan-Meier estimates showed a significantly better OS for patients with an e-mail address (P < .001). In multivariate analysis integrating interaction terms, male gender (hazard ratio [HR] = 1.27; 95% CI, 1.15 to 1.41; P < .001), older age (HR = 1.02; 95% CI, 1.02 to 1.03; P < .001), de novo metastatic setting (HR = 2.63; 95% CI, 2.47 to 2.79; P < .001), and no e-mail address (HR = 1.63; 95% CI, 1.33 to 2.00; P < .001) were significantly associated with worse OS.

Conclusion: Our results support a strong association between the limited level of literacy and OS. A more in-depth study integrating variables such as socioeconomic level and location of residence would enrich these results.

FIG 1.

(A) Kaplan-Meier curves of OS according to having an e-mail address without adjustment. (B) Inverse Probability of Treatment-weighted Kaplan-Meier curves of OS according to having an e-mail address. OS, overall survival.

FIG 2.

Multivariate analysis integrating significant interaction terms for overall survival according to sex, age, mail, de novo metastatic, and type of cancer. HR, hazard ratio; IC, confidence interval.

FIG A1.

Love plot for absolute standardized mean differences before and after propensity score matching comparing covariate values.