Results of negative binomial regressions analysing over-the-counter medicine usage (n=18 272)
| Cardiovascular system | Gastrointestinal system | CNS | CNS pain | Musculoskeletal system | Dietary Supplements | |
|---|---|---|---|---|---|---|
| Variable | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) |
| Demographic | ||||||
| Age | 1.052*** (1.042 to 1.063) | 1.033*** (1.023 to 1.044) | 0.995 (0.985 to 1.004) | 1.009** (1.003 to 1.015) | 1.057*** (1.050 to 1.064) | 1.031*** (1.027 to 1.034) |
| Male | 0.963 (0.765 to 1.212) | 0.505*** (0.377 to 0.675) | 0.493*** (0.366 to 0.664) | 0.597*** (0.509 to 0.701) | 0.624*** (0.530 to 0.736) | 0.573*** (0.519 to 0.633) |
| Caucasian | 0.769 (0.304 to 1.947) | 1.305 (0.591 to 2.877) | 1.147 (0.569 to 2.314) | 0.720 (0.433 to 1.196) | 0.953 (0.501 to 1.814) | 0.746 (0.542 to 1.027) |
| Social | ||||||
| Education | ||||||
| None | Reference | Reference | Reference | Reference | Reference | Reference |
| Secondary | 1.465** (1.101 to 1.949) | 3.162*** (2.155 to 4.639) | 1.665* (1.126 to 2.463) | 1.883*** (1.523 to 2.328) | 1.700*** (1.380 to 2.094) | 1.659*** (1.454 to 1.892) |
| Postsecondary | 1.342 (0.859 to 2.095) | 3.457*** (2.113 to 5.656) | 2.346*** (1.476 to 3.730) | 2.032*** (1.542 to 2.676) | 1.486* (1.082 to 2.041) | 1.806*** (1.514 to 2.155) |
| Degree or higher | 1.539** (1.130 to 2.096) | 2.862*** (1.878 to 4.361) | 1.916** (1.253 to 2.928) | 1.943*** (1.541 to 2.450) | 2.051*** (1.651 to 2.549) | 2.045*** (1.781 to 2.348) |
| Health-related | ||||||
| Body mass index | 1.036** (1.013 to 1.059) | 0.989 (0.963 to 1.015) | 1.034** (1.011 to 1.058) | 1.021** (1.006 to 1.035) | 1.004 (0.987 to 1.021) | 0.986** (0.976 to 0.996) |
| Units of alcohol | 1.003 (0.992 to 1.013) | 1.004 (0.991 to 1.018) | 1.000 (0.987 to 1.014) | 1.000 (0.992 to 1.008) | 1.007 (0.999 to 1.014) | 0.998 (0.993 to 1.003) |
| Smoker | 1.412* (1.016 to 1.961) | 0.603* (0.379 to 0.962) | 1.375 (0.987 to 1.915) | 0.897 (0.717 to 1.122) | 0.669* (0.490 to 0.913) | 0.690*** (0.590 to 0.808) |
| Walking (per week) | ||||||
| None | Reference | Reference | Reference | Reference | Reference | Reference |
| <1 hour | 2.193* (1.141 to 4.214) | 0.721 (0.379 to 1.372) | 0.546 (0.267 to 1.115) | 1.268 (0.885 to 1.816) | 0.997 (0.647 to 1.536) | 1.174 (0.916 to 1.505) |
| 1–3 hours | 2.291** (1.228 to 4.275) | 1.250 (0.718 to 2.177) | 1.305 (0.728 to 2.337) | 1.375 (0.985 to 1.920) | 1.218 (0.823 to 1.801) | 1.403** (1.116 to 1.764) |
| 3+ hours | 3.106*** (1.676 to 5.758) | 1.004 (0.574 to 1.756) | 1.631 (0.918 to 2.896) | 1.422* (1.021 to 1.982) | 1.622* (1.104 to 2.384) | 1.519*** (1.211 to 1.907) |
| Physical exercise (per week) | ||||||
| None | Reference | Reference | Reference | Reference | Reference | Reference |
| <1 hour | 1.308 (0.899 to 1.903) | 1.045 (0.658 to 1.660) | 0.962 (0.620 to 1.490) | 0.963 (0.742 to 1.251) | 1.259 (0.950 to 1.669) | 1.158 (0.983 to 1.363) |
| 1–3 hours | 0.906 (0.660 to 1.244) | 1.231 (0.894 to 1.694) | 0.910 (0.652 to 1.271) | 0.971 (0.800 to 1.180) | 1.511*** (1.248 to 1.829) | 1.227** (1.089 to 1.383) |
| 3+ hours | 1.029 (0.746 to 1.421) | 1.190 (0.831 to 1.702) | 0.760 (0.509 to 1.136) | 0.939 (0.757 to 1.163) | 1.645*** (1.351 to 2.003) | 1.334*** (1.175 to 1.514) |
| Chronic health | ||||||
| Fatigue | 1.027 (0.741 to 1.425) | 1.033 (0.720 to 1.483) | 0.860 (0.592 to 1.249) | 1.076 (0.872 to 1.327) | 0.806 (0.627 to 1.035) | 1.086 (0.940 to 1.254) |
| Pain | 1.192 (0.896 to 1.585) | 1.938*** (1.424 to 2.639) | 2.765*** (2.027 to 3.772) | 3.457*** (2.908 to 4.111) | 1.449*** (1.192 to 1.763) | 1.140* (1.005 to 1.293) |
| Insomnia | 1.084 (0.715 to 1.645) | 0.989 (0.642 to 1.522) | 1.554* (1.031 to 2.342) | 1.084 (0.834 to 1.408) | 1.135 (0.843 to 1.528) | 1.091 (0.907 to 1.311) |
| Anxiety | 1.114 (0.756 to 1.640) | 1.505* (1.031 to 2.197) | 1.228 (0.830 to 1.816) | 1.009 (0.792 to 1.286) | 0.701* (0.509 to 0.963) | 1.079 (0.911 to 1.277) |
| Depression | 0.940 (0.601 to 1.471) | 1.364 (0.888 to 2.094) | 1.360 (0.902 to 2.052) | 1.131 (0.871 to 1.469) | 0.880 (0.612 to 1.266) | 1.201 (0.996 to 1.447) |
| Diabetes | 0.840 (0.559 to 1.263) | 0.327** (0.142 to 0.752) | 0.456* (0.210 to 0.994) | 0.857 (0.616 to 1.194) | 0.597* (0.403 to 0.883) | 0.770* (0.623 to 0.952) |
| Breathing problems | 0.615* (0.412 to 0.917) | 1.121 (0.764 to 1.646) | 0.772 (0.496 to 1.200) | 0.991 (0.786 to 1.249) | 0.925 (0.714 to 1.197) | 1.042 (0.897 to 1.210) |
| High blood pressure | 1.189 (0.922 to 1.533) | 0.952 (0.684 to 1.326) | 0.808 (0.548 to 1.192) | 0.653*** (0.527 to 0.810) | 0.682*** (0.557 to 0.834) | 0.976 (0.861 to 1.106) |
| Heart disease | 1.103 (0.751 to 1.618) | 0.855 (0.491 to 1.491) | 0.850 (0.423 to 1.709) | 0.489*** (0.329 to 0.725) | 0.599** (0.416 to 0.863) | 0.861 (0.698 to 1.061) |
| Osteoarthritis | 1.015 (0.729 to 1.412) | 1.646** (1.165 to 2.324) | 1.359 (0.909 to 2.031) | 1.359** (1.088 to 1.700) | 1.720*** (1.403 to 2.107) | 1.268** (1.089 to 1.477) |
| Stroke | 1.225 (0.664 to 2.262) | 0.545 (0.170 to 1.749) | 0.490 (0.119 to 2.025) | 0.842 (0.471 to 1.504) | 0.337* (0.138 to 0.822) | 0.560** (0.374 to 0.840) |
| Cancer | 0.624 (0.322 to 1.209) | 0.421 (0.155 to 1.148) | 1.514 (0.766 to 2.990) | 0.903 (0.584 to 1.396) | 1.134 (0.777 to 1.655) | 0.840 (0.637 to 1.107) |
| Constant | 0.000*** (0.000 to 0.000) | 0.001*** (0.000 to 0.004) | 0.004*** (0.001 to 0.012) | 0.011*** (0.006 to 0.023) | 0.001*** (0.000 to 0.002) | 0.033*** (0.021 to 0.052) |
| ln α | 0.954 | −0.118 | −35.436 | 1.382 | −1.068 | 1.164 |
| α | 2.595 | 0.889 | 0.000 | 3.981 | 0.344 | 3.202 |
| Pseudo r2 | 0.072 | 0.087 | 0.0829 | 0.062 | 0.110 | 0.047 |
GP surgery was also adjusted for, including each surgery in the model as binary variables but not included in the table.
Significance levels: *<0.05, **<0.01, ***<0.001.
CNS, central nervous system; IRR, incident rate ratio.