Failure to comply with medical directions. The OPHA study identified a number of examples of persons who would not comply with medical direction, due to an inability to read written instructions or because verbal instructions were not presented in a way in which they could be understood. Literacy can impede the ability to understand the risks of medical procedures. A recent court ruling in British Columbia indicated that a written consent form, presented in technical language, did not meet the requirements for informed consent.(9)

Errors in administration of infant formula. The OPHA research study identified a number of instances reported by public health nurses where infant formula was misused, placing babies at risk. For example, a number of nurses reported that some mothers were not diluting concentrated formulas, and others were diluting ready-to-feed formulas.

Safety risks in the workplace, the community and at home. The Manitoba review of literacy and health indicated that: “Difficulty comprehending precautions on farm and recreational machinery such as all-terrain vehicles, watersleds, snowmobiles and farm equipment of all sorts, makes rural life more dangerous.” A report of the Ontario Advisory Council on Occupational Health and Safety cited a number of cases where literacy difficulties resulted in accidents, including inability to understand safety instructions when handling chemicals and “a pictorial instruction material demonstrating ‘how not to’ carry out a task was interpreted as a ‘how to’ instruction and the result was an increase in accidents.”

As significant and dramatic as these direct effects may be, a striking finding from the research is that the major impacts of literacy on health occur indirectly. The relationship between literacy and a range of factors which, in turn, are known to have major impacts on people’s health, has been extensively documented.

The Federal/Provincial/Territorial Advisory Committee on Population Health, in its 1994 Health Canada report, Strategies for Population Health - Investing in the Health of Canadians, has identified five major determinants of health:

• Living and Working Conditions
• Personal Health Practices and Coping Skills
• Physical Environment
• Health Services
• Biology and Genetic Endowment

Of these, “Biology and Genetic Endowment” is the only one which is not affected, at least to some degree, by literacy. We provide examples below of the role of literacy in influencing and interacting with the remaining four determinants of health.

9 MD’s failure to use plain language can lead to the courtroom, by Deborah Gordon, Canadian Medical Association Journal 15 Oct. 1996; 155(8) [Carpenter v. Finch. 1993].