Reexamination of hemoglobin adjustments to define anemia: altitude and smoking.

The correct interpretation of hemoglobin (Hb) to identify anemia requires adjusting for altitude and smoking. Current adjustments were derived using data collected before 1985, from low-income preschool-aged children (PSC) in the United States and indigenous men in Peru for altitude, and from White women of reproductive age (WRA) in the United States for smoking. Given the oldness and limited representativeness of these data, we reexamined associations between Hb and altitude and/or smoking using 13 population-based surveys and 1 cohort study each conducted after 2000. All WHO regions except South-East Asia were represented. The dataset included 68,193 observations among PSC (6-59 months) and nonpregnant WRA (15-49 years) with data on Hb and altitude (-28 to 4000 m), and 19,826 observations among WRA with data on Hb and smoking (status or daily cigarette quantity). Generalized linear models were used to assess the robustness of associations under varying conditions, including controlling for inflammation-corrected iron and vitamin A deficiency. Our study confirms that Hb should be adjusted for altitude and/or smoking; these adjustments are additive. However, recommendations for Hb adjustment likely need updating. Notably, current recommendations may underadjust Hb for light smokers and for those residing at lower altitudes and overadjust Hb for those residing at higher altitudes.

Early term delivery and health care utilization in the first year of life.

OBJECTIVE: To assess health care utilization during the first year of life among early term-born infants. STUDY DESIGN: We assessed health care utilization of 22420 singleton term infants (37-42 weeks gestational age [GA]) without major birth defects, fetal growth restriction, or exposure to diabetes or hypertension in utero, delivered between 1998 and 2007 and continuously enrolled at Kaiser Permanente Northwest for 12 months after delivery. GA, duration of delivery hospitalization, and postdelivery rehospitalizations and sick/emergency room visits in the first year of life were obtained from electronic medical records. Logistic regression models were used to estimate associations between GA and number of hospitalizations and length of stay. Generalized linear models were used to estimate the adjusted mean number of sick/emergency visits. RESULTS: Overall, 20.9% of term infants were born early. Infants delivered vaginally at 37 weeks GA had a 2.2 greater odds (95% CI, 1.6-3.1) of staying 4 or more days compared with those born at 39-40 weeks GA. Similar association was found among infants delivered by cesarean delivery at 37 or 38 weeks GA. Infants born at 37 weeks GA had increased odds of being rehospitalized within 2 weeks of delivery (OR, 2.6; 95% CI, 1.9-3.6). The adjusted mean number of sick/emergency room visits was higher for infants born at 37 and 38 weeks GA than for those born at 39-40 weeks GA (8.1, 7.7, and 7.3, respectively; P < .0001). CONCLUSIONS: Early term-born infants had greater health care utilization during their entire first year of life than infants born at 39-40 weeks GA.