The costs of limited health literacy: a systematic review

To summarize evidence about (1) the costs of limited health literacy (HL) and (2) the cost-effectiveness of interventions to improve limited HL. We performed a systematic review searching electronic databases and additional information resources. We included observational studies and interventional studies with HL-outcomes. We included populations at high risk for low HL and patients with (1) diabetes mellitus or (2) hyperlipidemia. We retrieved 2,340 papers and included 10 studies for analysis. The prevalence of limited HL is considerable (range 34-59%). On the health system level, the additional costs of limited HL range from 3 to 5% of the total health care cost per year. On the patient level, the additional expenditures per year per person with limited HL compared to persons with adequate HL range from US $143 to 7,798. Data on the cost-effectiveness of interventions to improve limited HL are scarce. The costs of limited HL may be substantial, but few studies were retrieved and the results are heterogeneous.