Crude and adjusted mean hemoglobin values by season and clinical center
. | . | Model 1 . | . | Model 2 . | . | Model 3 . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
. | No. patients . | Crude mean (SEM) . | P . | Adjusted mean*(SEM) . | P . | Adjusted mean†(SEM) . | P . | |||
| Ferrara, Italy | ||||||||||
| Summer | 254 | 9.13 (0.10) | – | 9.12 (0.9) | – | 9.25 (0.10) | – | |||
| Fall | 233 | 9.29 (0.10) | .001 | 9.29 (0.10) | .001 | 9.24 (0.10) | .995 | |||
| Winter | 220 | 9.36 (0.10) | <.001 | 9.38 (0.10) | .000 | 9.25 (0.10) | .994 | |||
| Spring | 241 | 9.28 (0.10) | .001 | 9.28 (0.10) | .001 | 9.32 (0.10) | .162 | |||
| Cagliari, Italy | ||||||||||
| Summer | 376 | 9.68 (0.08) | – | 9.70 (0.15) | – | 9.71 (0.15) | – | |||
| Fall | 380 | 9.88 (0.08) | .001 | 9.88 (0.15) | .001 | 9.85 (0.15) | .001 | |||
| Winter | 386 | 9.83 (0.08) | .001 | 9.84 (0.14) | .001 | 9.74 (0.15) | .541 | |||
| Spring | 387 | 9.64 (0.08) | .230 | 9.64 (0.15) | .128 | 9.75 (0.15) | .388 | |||
| Philadelphia, PA | ||||||||||
| Summer | 144 | 9.39 (0.11) | – | 9.38 (0.12) | – | 9.51 (0.13) | – | |||
| Fall | 140 | 9.70 (0.11) | .001 | 9.65 (0.18) | .001 | 9.61 (0.12) | .362 | |||
| Winter | 117 | 9.62 (0.12) | .002 | 9.64 (0.12) | .001 | 9.48 (0.14) | .837 | |||
| Spring | 143 | 9.56 (0.11) | .016 | 9.59 (0.12) | .002 | 9.61 (0.12) | .248 | |||
| Sydney, Australia‡ | ||||||||||
| Summer | 271 | 9.96 (0.11) | – | 9.98 (0.11) | – | 9.97 (0.11) | – | |||
| Fall | 224 | 9.88 (0.11) | .207 | 9.90 (0.11) | .285 | 9.90 (0.11) | .343 | |||
| Winter | 230 | 9.85 (0.11) | .112 | 9.86 (0.11) | .107 | 9.86 (0.11) | .388 | |||
| Spring | 231 | 9.87 (0.11) | .190 | 9.84 (0.11) | .06 | 9.84 (0.11) | .144 | |||
. | . | Model 1 . | . | Model 2 . | . | Model 3 . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
. | No. patients . | Crude mean (SEM) . | P . | Adjusted mean*(SEM) . | P . | Adjusted mean†(SEM) . | P . | |||
| Ferrara, Italy | ||||||||||
| Summer | 254 | 9.13 (0.10) | – | 9.12 (0.9) | – | 9.25 (0.10) | – | |||
| Fall | 233 | 9.29 (0.10) | .001 | 9.29 (0.10) | .001 | 9.24 (0.10) | .995 | |||
| Winter | 220 | 9.36 (0.10) | <.001 | 9.38 (0.10) | .000 | 9.25 (0.10) | .994 | |||
| Spring | 241 | 9.28 (0.10) | .001 | 9.28 (0.10) | .001 | 9.32 (0.10) | .162 | |||
| Cagliari, Italy | ||||||||||
| Summer | 376 | 9.68 (0.08) | – | 9.70 (0.15) | – | 9.71 (0.15) | – | |||
| Fall | 380 | 9.88 (0.08) | .001 | 9.88 (0.15) | .001 | 9.85 (0.15) | .001 | |||
| Winter | 386 | 9.83 (0.08) | .001 | 9.84 (0.14) | .001 | 9.74 (0.15) | .541 | |||
| Spring | 387 | 9.64 (0.08) | .230 | 9.64 (0.15) | .128 | 9.75 (0.15) | .388 | |||
| Philadelphia, PA | ||||||||||
| Summer | 144 | 9.39 (0.11) | – | 9.38 (0.12) | – | 9.51 (0.13) | – | |||
| Fall | 140 | 9.70 (0.11) | .001 | 9.65 (0.18) | .001 | 9.61 (0.12) | .362 | |||
| Winter | 117 | 9.62 (0.12) | .002 | 9.64 (0.12) | .001 | 9.48 (0.14) | .837 | |||
| Spring | 143 | 9.56 (0.11) | .016 | 9.59 (0.12) | .002 | 9.61 (0.12) | .248 | |||
| Sydney, Australia‡ | ||||||||||
| Summer | 271 | 9.96 (0.11) | – | 9.98 (0.11) | – | 9.97 (0.11) | – | |||
| Fall | 224 | 9.88 (0.11) | .207 | 9.90 (0.11) | .285 | 9.90 (0.11) | .343 | |||
| Winter | 230 | 9.85 (0.11) | .112 | 9.86 (0.11) | .107 | 9.86 (0.11) | .388 | |||
| Spring | 231 | 9.87 (0.11) | .190 | 9.84 (0.11) | .06 | 9.84 (0.11) | .144 | |||
For statistical comparison, summer was taken as the reference category.
– indicates no P value.
Cross-sectional time-series general linear model adjusted for age, sex, interval between transfusions, and amount of blood transfused during the previous visit
Cross-sectional time-series general linear model adjusted for the same variables as Model 2 and also monthly average temperature
For centers in Sydney, summer was defined as being December through February; fall, March through May; winter, June through August; and spring, September through November