Table 4.
Incidence and incidence rate ratios of visits for gingivitis and periodontitis in the rheumatoid arthritis cohort and the comparison cohort
| Disorder | Age group | Rheumatoid arthritis cohort | Comparison cohort | IRR (95% CI) | aIRR (95% CI) | ||||
|---|---|---|---|---|---|---|---|---|---|
| (ICD-9-CM) | (Years) | No. of patient | Person-years | Incidence | No. of patient | Person-years | Incidence | p value | p value |
| Gingivitisa (523.0, 523.1, 523.2) | |||||||||
| Overall | 419 | 5938 | 70.56 | 3805 | 60,310 | 63.09 |
1.12 (1.01–1.24) 0.030 |
1.13 (1.01–1.25) 0.027 |
|
| Sex | |||||||||
| Male | 67 | 1357 | 49.37 | 817 | 13,499 | 60.52 |
0.82 (0.64–1.05) 0.109 |
0.86 (0.66–1.11) 0.241 |
|
| Female | 352 | 4581 | 76.84 | 2988 | 46,811 | 63.83 |
1.20 (1.08–1.34) 0.001 |
1.19 (1.06–1.34) 0.003 |
|
| Age group (years) | |||||||||
| 20–54 | 269 | 3258 | 82.57 | 2443 | 33,870 | 72.13 |
1.14 (1.01–1.30) 0.036 |
1.17 (1.02–1.33) 0.022 |
|
| > 55 | 150 | 2680 | 55.97 | 1362 | 26,440 | 51.51 |
1.09 (0.92–1.29) 0.334 |
1.09 (0.92–1.30) 0.330 |
|
|
Periodontitisb (523.3, 523.4, 523.5, 523.8) | |||||||||
| Overall | 694 | 4049 | 171.40 | 6239 | 40,686 | 153.35 |
1.12 (1.03–1.21) 0.005 |
1.13 (1.04–1.22) 0.004 |
|
| Sex | |||||||||
| Male | 144 | 989 | 145.60 | 1381 | 8943 | 154.42 |
0.94 (0.79–1.12) 0.503 |
1.00 (0.83–1.19) 0.962 |
|
| Female | 550 | 3060 | 179.74 | 4858 | 31,743 | 153.04 |
1.17 (1.08–1.28) < 0.001 |
1.17 (1.07–1.28) 0.001 |
|
| Age group (years) | |||||||||
| 20–54 | 405 | 2207 | 183.51 | 3722 | 22,673 | 164.16 |
1.12 (1.01–1.24) 0.033 |
1.15 (1.03–1.28) 0.013 |
|
| > 55 | 289 | 1842 | 156.89 | 2517 | 18,013 | 139.73 |
1.12 (0.99–1.27) 0.063 |
1.14 (1.00–1.29) 0.043 |
|
Adjusted for age, sex, socioeconomic status, geographic region, hypertension, diabetes, congestive heart failure, chronic pulmonary disease, cancer, dyslipidemia, coronary artery disease, prior myocardial infarction, peripheral vascular disease, cerebrovascular disease, dementia, musculoskeletal disorders, peptic ulcer disease, chronic kidney disease, and liver disease
aIRR, adjusted incidence rate ratio; ICD-9-CM, International Classification of Diseases, Ninth revision, clinical modification; IRR, incidence rate ratio
aPatients who were diagnosed with gingivitis within 90 days before the index date were excluded and 1288 patients with rheumatoid arthritis and 13,019 controls were included in the analysis
bPatients who were diagnosed with periodontitis within 90 days before the index date were excluded and 1248 patients with rheumatoid arthritis and 12,152 controls were included in the analysis