Introduction
Methods
Data source and sample selection
Outcome variable
Exposure variable
Other covariates
Estimation strategy
Results
Descriptive analyses
Characteristics | Baseline wave (2009) | Final wave (2017) | Pooled data (2009, 2013 & 2017) | |||
---|---|---|---|---|---|---|
n | % | n | % | n | % | |
Socio-economic, and demographic characteristics | ||||||
Age group | ||||||
15–29 years | 105 | 46.05 | 199 | 48.66 | 492 | 48.86 |
30–44 years | 59 | 25.88 | 100 | 24.45 | 253 | 25.12 |
45–59 years | 47 | 20.61 | 76 | 18.58 | 185 | 18.37 |
≥ 60 years | 17 | 7.46 | 34 | 8.31 | 77 | 7.65 |
Sex | ||||||
Male | 88 | 38.60 | 175 | 42.79 | 425 | 42.20 |
Female | 140 | 61.40 | 234 | 57.21 | 582 | 57.80 |
Marital status | ||||||
Single | 127 | 55.70 | 201 | 49.14 | 531 | 52.73 |
Partnered | 101 | 44.30 | 208 | 50.86 | 476 | 47.27 |
Highest education level attained | ||||||
Year 12 and below | 156 | 68.42 | 227 | 55.50 | 602 | 59.78 |
Certificate course | 54 | 23.68 | 144 | 35.21 | 312 | 30.98 |
University degree | 18 | 7.89 | 38 | 9.29 | 93 | 9.24 |
Annual household income | ||||||
Lowest quintile (Poorest) | 46 | 20.18 | 82 | 20.05 | 202 | 20.06 |
Second quintile | 46 | 20.18 | 82 | 20.05 | 201 | 19.96 |
Middle quintile | 45 | 19.74 | 83 | 20.29 | 202 | 20.06 |
Fourth quintile | 46 | 20.18 | 81 | 19.80 | 201 | 19.96 |
Highest quintile (Richest) | 45 | 19.74 | 81 | 19.80 | 201 | 19.96 |
Labour-market status | ||||||
Employed | 116 | 50.88 | 196 | 47.92 | 490 | 48.66 |
Unemployed or NILF | 112 | 49.12 | 213 | 52.08 | 517 | 51.34 |
Area of residence | ||||||
Major city | 105 | 46.05 | 180 | 44.01 | 463 | 45.98 |
Regional/Remote area | 123 | 53.95 | 229 | 55.99 | 544 | 54.02 |
Lifestyle factors | ||||||
Smoking status | ||||||
Never smoked | 81 | 35.53 | 145 | 35.45 | 362 | 35.95 |
Ex-smoker | 51 | 22.37 | 100 | 24.45 | 240 | 23.83 |
Current smoker | 96 | 42.11 | 164 | 40.10 | 405 | 40.22 |
Alcohol drinking | ||||||
Never drunk | 17 | 7.46 | 45 | 11.1 | 97 | 9.63 |
Used to drink | 26 | 11.40 | 72 | 17.60 | 149 | 14.80 |
Currently drinks | 185 | 81.14 | 292 | 71.39 | 761 | 75.57 |
Physical exercise | ||||||
Less than the recommended level | 158 | 69.30 | 300 | 73.35 | 716 | 71.10 |
Recommended level | 70 | 30.70 | 109 | 26.65 | 291 | 28.90 |
Health-related factors | ||||||
BMI category | ||||||
Underweight | 37 | 16.23 | 60 | 14.67 | 153 | 15.19 |
Healthy weight | 69 | 30.26 | 99 | 24.21 | 268 | 26.61 |
Overweight | 65 | 28.51 | 112 | 27.38 | 280 | 27.81 |
Obese | 57 | 25.00 | 138 | 33.74 | 306 | 30.39 |
Variables | Baseline wave (2009) | Final wave (2017) | Pooled data (2009, 2013, & 2017) | |||
---|---|---|---|---|---|---|
n | Mean (SD) | n | Mean (SD) | n | Mean (SD) | |
SF-36 domain scores | ||||||
Physical functioning | 228 | 83.09 (24.23) | 409 | 78.39 (26.31) | 1007 | 80.03 (25.44) |
Role physical | 228 | 76.31 (38.32) | 409 | 77.56 (35.79) | 1007 | 77.77 (36.60) |
Role emotional | 228 | 80.26 (36.15) | 409 | 77.26 (36.92) | 1007 | 78.33 (36.58) |
Social functioning | 228 | 76.75 (26.80) | 409 | 75.45 (25.56) | 1007 | 76.30 (25.58) |
Mental health | 228 | 71.59 (18.71) | 409 | 67.04 (19.30) | 1007 | 68.78 (19.28) |
Vitality | 228 | 59.09 (21.48) | 409 | 55.26 (20.09) | 1007 | 56.70 (20.75) |
Bodily pain | 228 | 74.03 (24.87) | 409 | 69.15 (25.68) | 1007 | 70.94 (25.65) |
General health | 228 | 65.46 (21.97) | 409 | 60.71 (21.62) | 1007 | 62.82 (21.81) |
SF-36 component summary scores | ||||||
PCS | 228 | 49.39 (10.56) | 409 | 48.33 (10.17) | 1007 | 48.80 (10.26) |
MCS | 228 | 46.87 (11.61) | 409 | 45.11 (11.60) | 1007 | 45.81 (11.58) |
SF-6D | 228 | 0.75 (0.13) | 409 | 0.72 (0.13) | 1007 | 0.73 (0.13) |
Number of chronic conditions (% observations) | ||||||
0 (No morbidity) | 127 | 55.7 | 198 | 48.41 | 522 | 51.84 |
1 (Single chronic condition) | 65 | 28.51 | 115 | 28.12 | 271 | 26.91 |
≥ 2 (Multimorbidity) | 36 | 15.79 | 96 | 23.47 | 214 | 21.25 |
Number of chronic conditions | Number of chronic conditions | ||
---|---|---|---|
0 (No morbidity), n (%) | 1 (Single chronic condition), n (%) | ≥ 2 (Multimorbidity), n (%) | |
0 (No morbidity) | 166 (73.78) | 44 (19.56) | 15 (6.67) |
1 (Single chronic condition) | 32 (29.63) | 52 (48.15) | 24 (22.22) |
≥ 2 (Multimorbidity) | 2 (2.44) | 15 (18.29) | 65 (79.27) |
Regression modelling
Model | Outcome | Coefficient on single chronic condition (SE), p-value | Coefficient on multimorbidity (SE), p-value | Wald test: β single chronic condition = β multimorbidity, p-value |
---|---|---|---|---|
Model 1 | PCS | – 2.942 (0.961), 0.002 | – 6.527 (1.579), < 0.001 | 0.0065 |
Model 2 | MCS | – 0.824 (1.036), 0.452 | – 3.765 (1.590), 0.018 | 0.041 |
Model 3 | SF-6D | – 0.036 (0.013), 0.006 | – 0.075 (0.017), < 0.001 | 0.008 |
Model | Outcome | Coefficient on single chronic condition (SE), p-value | Coefficient on multimorbidity (SE), p-value | Wald test: β single chronic condition = β multimorbidity, p-value |
---|---|---|---|---|
Model 1 | PF | – 6.57 (2.43), 0.01 | – 13.40 (3.28), < 0.001 | 0.01 |
Model 2 | RP | – 5.05 (4.43), 0.25 | – 23.05 (6.10), < 0.001 | 0.0004 |
Model 3 | RE | – 4.70 (4.20), 0.26 | – 12.25 (6.84), 0.07 | 0.20 |
Model 4 | SF | – 4.17 (2.39), 0.08 | – 15.88 (3.64), < 0.001 | 0.0005 |
Model 5 | MH | – 2.83 (1.78), 0.11 | – 8.72 (2.65), 0.001 | 0.01 |
Model 6 | VT | – 2.03 (1.87), 0.28 | – 5.80 (2.52), 0.02 | 0.09 |
Model 7 | BP | – 9.84 (2.33), < 0.001 | – 15.81 (3.69), < 0.001 | 0.07 |
Model 8 | GH | – 3.34 (1.96), 0.09 | – 11.24 (2.98), < 0.001 | 0.003 |