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Measuring Physical and Mental Health in the IALSS
Health in the IALSS is measured using responses to a series of questions designed to estimate two scales: the Physical Component Summary (PCS) and the Mental Component Summary (MCS). These scales are internationally validated indicators of self-reported physical and mental health. In the IALSS they are measured on the basis of responses to 12 questions known as the SF-12. These 12 questions capture over 90 percent of the variance in a much larger 36-item instrument known as the SF-36. The abbreviated version reduces the burden on respondents and offers a practical way of measuring respondents’ health. By applying weights to each response, the 12 questions can be used to calculate the PCS and MCS scales (for more information about these physical and mental health measures, please visit www.sf-36.org).
For the analysis in this chapter, the resulting PCS and MCS scale scores were grouped into national quartiles. This procedure assigned the boundaries for four analytical groups, each comprising 25 percent of the population, and labelled “poor”,“ fair”, “good” and “excellent”. Thus, the group with poor health is composed of the lowest scoring 25 percent of the population, measured nationally, while those in the group with excellent health are part of the highest scoring 25 percent.
The analysis of health and literacy focuses on the document literacy domain. Health care instructions and directions for taking medicines typically correspond to the general competencies measured by document literacy.
Analysis of the average document literacy score for each mental health grouping provides no support for a connection between mental health and document literacy. Indeed, in all provinces and territories, the distribution of literacy scores either does not vary significantly with differences in the respondents’ perceived mental health, whether poor, fair, good or excellent, or the average scores fluctuate unpredictably.
In contrast, the results of an analysis of the physical health groupings suggest the existence of a relationship between physical health and literacy proficiency. Given the relationship between aging and physical health, with those over 65 having a much higher proportion reporting poor health, the analysis is presented for two age groups: 16 to 65 year-olds and over 65.
At the Canada level, for both age groups, literacy scores are lower for those who report being in poor physical health. The average document literacy score of those aged 16 to 65 who reported being in poor health is 267 – corresponding to Level 2 proficiency. For those in fair, good or excellent health, the average score is 284 – corresponding to Level 3 proficiency (Table 5.1).
In most jurisdictions, 16 to 65 year-olds in poor health have lower average document literacy scores than those reporting better health. Table 5.1 orders the provinces and territories by the size of the difference in average document literacy between those in poor health and those in fair, good or excellent health. For 16 to 65 year-olds, this difference is smallest in the Yukon and Northwest Territories.