Observed and expected incidence of cases in NOAR and in three sub-populations
| Area | Population aged >15 | Inflammatory polyarthritis | Rheumatoid arthritis | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Number of cases 1990–95 | Incidence /100 000 pyr | Number of expected cases1-150 | p Value† | Number of cases 1990–95 | Incidence /100 000 pyr | Number of expected cases1-150 | p Value† | |||
| NOAR | 413 421 | 1476 | 51 | 962 | 32 | |||||
| A | 532 | 7 | 219 | 1.6 | 0.001 | 6 | 188 | 1.0 | 0.0007 | |
| B | 694 | 6 | 144 | 2.1 | 0.03 | 5 | 120 | 1.3 | 0.0093 | |
| C | 85 | 5 | 980 | 0.28 | 0.00092 | 3 | 588 | 0.16 | 0.0001 | |
↵1-150 Based on NOAR incidence. †Probability based on Poisson distribution of observed or greater number of cases occurring by chance. pyr = person years.