A cost analysis comparing erythropoietin and red cell transfusions in the treatment of anemia of prematurity

BACKGROUND: Anemia of prematurity is invariably observed in very low birth weight infants and may become symptomatic enough to be treated with packed red cell transfusions. Recently, treatment of this condition with recombinant human erythropoietin has been advocated. STUDY DESIGN AND METHODS: To compare the costs of training symptomatic anemia in hospitalized premature infants with transfusions alone or with erythropoietin plus red cell transfusions as needed, cost estimates were derived from local hospital and published cost data. Decision analysis and sensitivity analysis were applied to a "base case." The base case was derived from results of a multicenter erythropoietin trial in the United States in which premature infants received 500 U of erythropoietin per kg of body weight each week. Because erythropoietin treatment began on average at 3 weeks of life, when infants were clinically stable, they had already received 3.5 red cell transfusions. During the 6-week treatment period, erythropoietin- treated infants received significantly fewer additional transfusions: a mean of 1.6 versus 1.1. RESULTS: The base-case cost in 1993 dollars for treating anemia in hospitalized premature infants with erythropoietin and transfusions was $1,326. This was nearly twice the cost of conventional treatment with transfusions alone ($721). If the 6-week treatment period alone is considered, erythropoietin is 3.6 times more costly: $840 versus $235. CONCLUSION: The largest available US study using erythropoietin to treat anemia in premature infants has demonstrated a small, but significant, reduction in transfusion needs. However, this study's cost data alone do not justify the widespread use of erythropoietin in premature infants. When this issue is probed in great depth, sensitivity analyses demonstrate that major reductions in erythropoietin's cost and/or improvements in its effectiveness quite possibly will make its use economically more attractive.     

Development of postural adjustments during reaching in typically developing infants from 4 to 18 months

Knowledge on the development of postural adjustments during infancy, in particular on the development of postural muscle coordination, is limited. This study aimed at the evaluation of the development of postural control during reaching in a supported sitting condition. Eleven typically developing infants participated in the study and were assessed at the ages of 4, 6, 10 and 18 months. We elicited reaching movements by presenting small toys at an arm’s length distance, whilst activity of multiple arm, neck and trunk muscles was recorded using surface EMG. A model-based computer algorithm was used to detect the onset of phasic muscle activity. The results indicated that postural muscle activity during reaching whilst sitting supported is highly variable. Direction-specific postural activity was inconsistently present from early age onwards and increased between 10 and 18 months without reaching a 100 % consistency. The dominant pattern of activation at all ages was the ‘complete pattern’, in which all direction-specific muscles were recruited. At 4 months, a slight preference for top-down recruitment existed, which was gradually replaced by a preference for bottom-up recruitment. We conclude that postural control during the ecological task of reaching during supported sitting between 4 and 18 months of age is primarily characterized by variation. Already from 4 months onwards, infants are—within the variation—sometimes able to select muscle recruitment strategies that are optimal to the task at hand.     

递增负荷有氧运动14周影响不同衰老程度老年男性的生物学年龄

目的:观察有氧运动对不同衰老程度老年男性生物学年龄的影响。方法:于2002-09/12选择上海市杨浦区退休老年男性13名,年龄59～76岁,平均(64±5)岁,近期无系统健身运动经历。13名老年男性采用功率自行车进行14周递增负荷有氧运动。以最大心率的75%所对应的运动负荷为训练强度;在第4,8周末重新确定运动强度,第5～8周、9～14周以新负荷作为健身运动负荷。每周3次,起始2周每次持续20min,以后每隔2周每次增加5min。采用刘继武等推荐的生物学年龄成套测试方法测定生物学年龄。运动前和运动后测定生物学年龄以及身体形态、心血管、肺功能等生理指标。并根据生物学年龄与实际年龄的差距,分成提前衰老组(生物学年龄大于实际年龄)和延缓衰老组(生物学年龄小于实际年龄)进行对照分析。结果:①老年男性运动前生物学年龄大于实际年龄,差异无显著性意义(P=0.56),有氧运动后生物学年龄小于实际年龄,差异无显著性意义(P=0.066),有氧运动后生物学年龄小于运动前,差异有非常显著性意义[分别为(65.13±6.33),(67.15±7.13)岁,P<0.01]。②根据生物学年龄与实际年龄的差距,将老年男性分成提前衰老组7名和延缓衰老组6名。提前衰老组老年男性有氧运动前生物学年龄大于实际年龄,递增负荷有氧运动后生物学年龄接近实际年龄,低于运动前,差异有非常显著性意义[分别为(69.00±6.73),(71.90±7.55)岁,P<0.01]。延缓衰老组有氧运动前生物学年龄小于实际年龄,有氧运动后生物学年龄进一步减少,低于运动前,差异无显著性意义(P>0.05)。③提前衰老组老年男性有氧运动后腰围低于运动前,腰臀比高于运动前,差异有显著性意义[分别为(94.20±5.14),(99.58±6.48)cm;(0.95±0.03),(0.92±0.04)cm,P<0.05]。延缓衰老组老年男性上臂皮褶厚度低于运动前,差异有显著性意义[分别为(11.00±2.17),(14.42±2.33)mm,P<0.05]。其他身体形态指标变化差异无显著性意义。生理功能指标变化较明显,最大摄氧量、闭眼单脚站立时间均高于运动前,差异有显著性意义[分别为(36.08±5.40),(30.08±2.21)mL/(kg·min);(28.17±20.51),(12.4±14.78)s,P<0.05]。④两组老年男性有氧运动后心血管和肺功能指标中收缩压、舒张压均有下降,肺活量增加。其中延缓衰老组老年男性肺活量高于运动前,差异有显著性意义[分别为(3.98±0.69),(3.61±0.71)L,P<0.05]。结论:有氧运动对不同衰老程度老年男性生物学年龄、身体形态和生理功能均可产生良性影响,达到延缓衰老目的。     

Prevalence of hearing impairment and associated factors in school-aged children and adolescents: a systematic review

Introduction

Hearing impairment is one of the communication disorders of the 21st century, constituting a public health issue as it affects communication, academic success, and life quality of students. Most cases of hearing loss before 15 years of age are avoidable, and early detection can help prevent academic delays and minimize other consequences.