Table 3.
Hazard ratios for mortality according to peri-RA* or peri-index* weight change, analyzed separately in the RA and comparison cohorts.
| Deaths/Person-years | Mortality rate** | Age-adjusted HR (95% CI)1 | Age and pre-RA/index BMI-adjusted HR (95% CI)2 | Multivariable HR (95% CI)3 | Multivariable and RA severity- adjusted HR (95% CI)4 | |
|---|---|---|---|---|---|---|
| RA cohort (n=902) | ||||||
| Severe Loss (>30 lb) | 19/275 | 6,909 | 3.51 (2.12–5.80) | 3.10 (1.80–5.33) | 2.78 (1.58–4.89) | 2.71 (1.54–4.77) |
| Moderate Loss (>20–30 lb) | 16/376 | 4,251 | 1.47 (0.86–2.52) | 1.36 (0.77–2.40) | 1.35 (0.76–2.38) | 1.32 (0.75–2.34) |
| Mild Loss (>10–20 lb) | 41/1,274 | 3,219 | 1.72 (1.22–2.42) | 1.71 (1.21–2.41) | 1.78 (1.25–2.54) | 1.75 (1.22–2.49) |
| Stable (±10 lb) | 218/10,530 | 2,070 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
| Mild Gain (>10–20 lb) | 51/2,229 | 2,288 | 1.26 (0.92–1.73) | 1.27 (0.93–1.74) | 1.21 (0.88–1.67) | 1.25 (0.90–1.74) |
| Moderate Gain (>20–30 lb) | 18/870 | 2,069 | 1.30 (0.79–2.14) | 1.33 (0.81–2.19) | 1.05 (0.63–1.75) | 1.08 (0.64–1.80) |
| Severe Gain (>30 lb) | 8/452 | 1,770 | 1.58 (0.76–3.28) | 1.44 (0.69–3.01) | 1.45 (0.69–3.07) | 1.57 (0.74–3.32) |
| Comparison cohort (n=7,884)*** | ||||||
| Severe Loss (>30 lb) | 55/1,480 | 3,717 | 2.98 (2.27–3.91) | 2.42 (1.81–3.22) | 2.16 (1.61–2.88) | - |
| Moderate Loss (>20–30 lb) | 69/2,311 | 2,986 | 1.87 (1.47–2.38) | 1.70 (1.33–2.18) | 1.50 (1.17–1.92) | - |
| Mild Loss (>10–20 lb) | 209/8,205 | 2,547 | 1.46 (1.26–1.68) | 1.39 (1.20–1.61) | 1.24 (1.06–1.43) | - |
| Stable (±10 lb) | 1,532/104,883 | 1,461 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | - |
| Mild Gain (>10–20 lb) | 296/22,892 | 1,293 | 1.14 (1.00–1.29) | 1.13 (1.00–1.28) | 1.09 (0.96–1.24) | - |
| Moderate Gain (>20–30 lb) | 94/6,625 | 1,419 | 1.34 (1.09–1.65) | 1.29 (1.05–1.59) | 1.20 (0.97–1.48) | - |
| Severe Gain (>30 lb) | 48/3,679 | 1,305 | 1.42 (1.06–1.89) | 1.36 (1.01–1.81) | 1.19 (0.89–1.59) | - |
Data on weight were obtained every two years in follow-up during the Nurses’ Health Study. The “peri-RA” period was defined as up to four years before and four years after RA diagnosis to capture early symptoms and the entire early RA period after diagnosis. The “peri-index” period was similarly defined as up to four years before and four years after index date for matched non-RA comparators.
Per 100,000 person-years
The comparison cohort was formed by matching each RA case with up to 10 women without RA based on same age and calendar year at the index date of RA diagnosis.
Adjusted for age (continuous, years) and calendar year.
Additionally adjusted for pre-RA/index date BMI (<18.5, 18.5–24.9, 25–29.9, 30–34.9, ≥35 kg/m2).
Additionally adjusted for cigarette smoking (never, past, current), physical activity (hours of moderate or vigorous exercise per week, continuous), census-tract household family income (<$40K, $40K+ per year), and Alternative Healthy Index dietary score (tertiles), and the Multimorbidity Weighted Index (continuous).
Additionally adjusted additionally adjusted for RA serostatus (seropositive, seronegative), rheumatoid nodules, and radiographic changes/erosions according to medical record review at RA diagnosis. This model was not applicable to the comparison cohort.
BMI, body mass index; CI, confidence interval; HR, hazard ratio; RA, rheumatoid arthritis; SD, standard deviation.