Lee et al. BMC Public Health 2010, 10:614 http://www.biomedcentral.com/1471-2458/10/614 years, 25-39 years, 40-49 years, 50-64 years, and ≥65 years; educational attainment: 0 year of formal school- ing, 1-6 years, 7-12 years, 13-16 years, and ≥17 years; prior year’s average household income: ≤50% national average (≤NT$461,937 or ≤US$14,435.5), 51%-75% national average (NT$461,938-NT$692,906 or US $14,435.6-US$21,653.3), 76%-100% national average (NT $692,907-NT$923,875 or US$21,653.4-US$28,871.1), >100% national average (>NT$923,875 or >US $28,871.1). Significant differences in health literacy across socio-demographic groups were evaluated using the chi-square (c2) test. The associations of health lit- eracy with health status and healthcare utilization were assessed using the c2 test and multinomial logit model- ing. The logit models controlled for age, gender, educa- tional attainment, household income, and residential location. For the logit models on health care utilization, physical health status and mental health status were also included as controls. The interval form of age and edu- cational attainment was used in the multinomial logit models to conserve statistical power. All statistical ana- lysis was performed using the Statistical Analysis Soft- ware package, SAS version 9.1. Results Sociodemographic Characteristics of the sample Respondents ranged in age from 18.6 to 92.8 years, with a mean age of 46.3. The gender distribution was about equal. The largest group of respondents had 7-12 years of formal schooling (40.0%) and the second largest had 13-16 years (32.2%). Three hundred and thirteen respondents (21.0%) did not report household income; 22.9% of respondents were in households that earned less than 50% of the national average household income in 2007, 16.9% earned 51-75% of the average, 12.5% earned 76-100% of the average, and 26.3% earned more than 100% of the average. The majority of respondents (58.7%) resided in metropolitan and mid-size cities, 21.7% in small cities, and 19.6% in rural/remote areas (Table 1). Page 3 of 8 % 69.7 86.6 86.8 80.5 63.1 23.2 69.2 70.3 0.0 33.7 73.4 95.0 98.4 49.1 73.4 82.9 88.0 58.2 78.8 72.3 69.1 54.4 X2-test p-value <0.001 0.07 <0.001 <0.001b <0.001 a The national average of annual household income in 2007 was around NT$923,875. (Source: Directorate General of Budget, Accounting and Statistics, Executive Yuan. Report on the Survey of Family Income and Expenditure in Taiwan Area of Republic of China.). Table 1 Socio-demographic Attributes and Health Literacy Level of a National Sample of Adults in Taiwan, 2008 N % MHLS Score Inadequate HL Marginal HL Adequate HL Entire Sample Age 18-24 years 25-39 years 40-49 years 50-64 years ≥65 years Gender Male Female Years of Schooling 0 year 1-6 years 7-12 years 13-16 years ≥17 years Household Incomea ≤50% of average 51-75% of average 76-100% of average >100% of average Missing Residential Location Metropolitan city Mid-size city Small city Rural/remote area 1493 100.0 149 456 292 358 237 736 757 105 246 597 481 64 342 252 193 393 313 367 509 324 292 10.0 30.5 19.6 24.0 15.9 49.3 50.7 7.0 16.5 40.0 32.2 4.3 22.9 16.9 12.9 26.3 21.0 24.6 34.1 21.7 19.6 mean (SD) 39.2 (14,8) 45.0 (6.2) 45.0 (6.6) 43.9 (7.1) 38.1 (14.8) 20.6 (20.2) 40.0 (13.5) 38.5 (15.9) 0.3 (3.4) 30.3 (17.6) 42.8 (6.8) 46.7 (2.8) 48.0 (2.4) 32.4 (18.4) 41.4 (11.6) 43.6 (9.4) 45.3 (6.5) 34.7(18.0) 42.0 (12.4) 41.2 (12.1) 38.8 (15.0) 32.7 (19.1) N 205 4 12 10 52 126 91 114 104 73 28 0 0 93 23 10 7 72 28 45 48 84 % 13.7 2.7 2.6 3.4 14.5 53.2 12.4 15.1 99.0 29.7 4.7 0.0 0.0 27.2 9.1 5.2 1.8 23.0 7.6 8.8 14.8 28.8 N 247 16 48 47 80 56 136 111 1 90 131 24 1 81 44 23 40 59 50 96 52 49 % 16.5 10.7 10.5 16.1 22.4 23.6 18.5 14.7 0.9 36.6 21.9 5.0 1.6 23.7 17.5 11.9 10.2 18.9 13.6 18.9 16.1 16.8 N 1041 129 396 235 226 53 509 532 0 83 438 457 63 168 185 160 346 182 289 368 224 159