Table 1.

Trends in anemia variables, by year

No. of ferritin measurements373020,69216,44914,09010,842
Unique patients (n)18214009416544003427
Interval since previous ferritin measurement
 2–3 wk44344
 4–5 wk7664363035
 6–11 wk611131412
 12–14 wk1421475046
 15–17 wk01124
 50–199 ng/ml1111756
 200–499 ng/ml3430221516
 500–799 ng/ml3130272426
 800–1199 ng/ml1820273735
 1200–1499 ng/ml55101311
 1500–5000 ng/ml24786
IV iron dose
 No dose 2430293232
 1–124 mg/mo1918121415
 125–249 mg/mo2621283031
 250–399 mg/mo1111988
 ≥400 mg/mo1920221715
Received bolus dose of IV iron1014222119
 < 20%1718151314
 <10 g/dl6781214
 10–11 g/dl1819244045
 11–12 g/dl4244503730
 ≥12 g/dl3430181111
ESA dose
 No dose2481013
 1–4999 U/wk1920243134
 5000–9999 U/wk1920222423
 10,000–24,999 U/wk3432302522
 ≥25,000 U/wk262417109
  • Unless otherwise noted, values are percentages with denominator as the number of ferritin measurements. There were 65,803 ferritin intervals (the time between two consecutive ferritin measurements) from 7434 unique patients. Intravenous iron dose and ESA dose were summed across all treatments during the interval and divided by the interval length. A bolus dose of intravenous iron was defined as receiving ≥500 mg of intravenous iron during any 2-week period during an interval. Hemoglobin was calculated as the mean of all hemoglobin measurements during the interval. Transferrin saturation at time of ferritin measurement was recorded. IV, intravenous; TSAT, transferrin saturation; ESA, erythropoiesis-stimulating agent.