This article discusses regression analysis of failure time under the additive hazards model, when the regression coefficients are time-varying. The regression coefficients are estimated locally based on the pseudo-sco...This article discusses regression analysis of failure time under the additive hazards model, when the regression coefficients are time-varying. The regression coefficients are estimated locally based on the pseudo-score function [12] in a window around each time point. The proposed method can be easily implemented, and the resulting estimators are shown to be consistent and asymptotically normal with easily estimated variances. The simulation studies show that our estimation procedure is reliable and useful.展开更多
目的通过术后早期及延迟负重比较,探讨小面积距骨骨软骨损伤(osteochondral lesion of the talus,OLT)行微骨折术后负重时间对疗效的影响,为指导术后康复锻炼提供依据。方法选择2010年3月-2011年9月收治的小面积OLT(<2 cm2)拟行微骨...目的通过术后早期及延迟负重比较,探讨小面积距骨骨软骨损伤(osteochondral lesion of the talus,OLT)行微骨折术后负重时间对疗效的影响,为指导术后康复锻炼提供依据。方法选择2010年3月-2011年9月收治的小面积OLT(<2 cm2)拟行微骨折术治疗的患者43例,随机分为术后早期负重组(n=22)和延迟负重组(n=21)。两组患者性别、年龄、体重指数、病程、损伤原因、术前疼痛视觉模拟评分(VAS)及美国矫形足踝协会(AOFAS)评分比较,差异均无统计学意义(P>0.05),具有可比性。两组患者均于关节镜下行关节面清理及微骨折术治疗。早期负重组患者术后即在"8"字护踝保护下完全负重,延迟负重组患者6周后开始逐渐负重。结果术中关节镜下测量,早期负重组软骨损伤面积为(1.24±0.35)cm2,延迟负重组为(1.25±0.42)cm2,损伤面积比较差异无统计学意义(t=0.09,P=0.93);两组软骨损伤分级比较差异亦无统计学意义(Z=—1.45,P=0.15)。术后两组患者均获随访,随访时间12~18个月,平均14.5个月。两组术后各时间点VAS及AOFAS评分均较术前显著改善(P<0.05);术后3、6、12个月两组间比较,差异均无统计学意义(P>0.05)。早期负重组回归工作时间为(6.35±1.93)个月,显著早于延迟负重组的(8.75±1.48)个月(t=—4.10,P=0.00)。结论对于小面积OLT,微骨折术后早期负重与延迟负重近期疗效相似,但早期负重患者回归工作时间显著提前。展开更多
基金supported by the Fundamental Research Funds for the Central Universities (QN0914)
文摘This article discusses regression analysis of failure time under the additive hazards model, when the regression coefficients are time-varying. The regression coefficients are estimated locally based on the pseudo-score function [12] in a window around each time point. The proposed method can be easily implemented, and the resulting estimators are shown to be consistent and asymptotically normal with easily estimated variances. The simulation studies show that our estimation procedure is reliable and useful.
文摘目的通过术后早期及延迟负重比较,探讨小面积距骨骨软骨损伤(osteochondral lesion of the talus,OLT)行微骨折术后负重时间对疗效的影响,为指导术后康复锻炼提供依据。方法选择2010年3月-2011年9月收治的小面积OLT(<2 cm2)拟行微骨折术治疗的患者43例,随机分为术后早期负重组(n=22)和延迟负重组(n=21)。两组患者性别、年龄、体重指数、病程、损伤原因、术前疼痛视觉模拟评分(VAS)及美国矫形足踝协会(AOFAS)评分比较,差异均无统计学意义(P>0.05),具有可比性。两组患者均于关节镜下行关节面清理及微骨折术治疗。早期负重组患者术后即在"8"字护踝保护下完全负重,延迟负重组患者6周后开始逐渐负重。结果术中关节镜下测量,早期负重组软骨损伤面积为(1.24±0.35)cm2,延迟负重组为(1.25±0.42)cm2,损伤面积比较差异无统计学意义(t=0.09,P=0.93);两组软骨损伤分级比较差异亦无统计学意义(Z=—1.45,P=0.15)。术后两组患者均获随访,随访时间12~18个月,平均14.5个月。两组术后各时间点VAS及AOFAS评分均较术前显著改善(P<0.05);术后3、6、12个月两组间比较,差异均无统计学意义(P>0.05)。早期负重组回归工作时间为(6.35±1.93)个月,显著早于延迟负重组的(8.75±1.48)个月(t=—4.10,P=0.00)。结论对于小面积OLT,微骨折术后早期负重与延迟负重近期疗效相似,但早期负重患者回归工作时间显著提前。