Corrigan J D, Bogner J A, Mysiw W J, Clinchot D, Fugate L
Department of Physical Medicine and Rehabilitation, Ohio State University, Columous, USA.
Arch Phys Med Rehabil. 1997 Feb;78(2):132-7. doi: 10.1016/s0003-9993(97)90253-7.
(1) Examine systematic biases created by subjects lost at 1-year follow-up in samples of persons with traumatic brain injury; (2) identify potential threats to generalization of outcomes data.
A consecutive sample of admissions to acute rehabilitation studied 1 year following discharge.
An inpatient brain injury rehabilitation unit in a large, academic medical center.
Eighty-eight patients with primary diagnosis of traumatic brain injury.
Subjects were considered lost to follow-up when phone calls, mail, clinic visits, and assistance from family failed to allow contact 1 year after discharge from acute rehabilitation. Potential effects of the biased follow-up sample were examined for seven suboptimal outcomes.
A total of 38.6% of subjects were lost to follow-up. Subjects intoxicated at time of injury and those with history of substance abuse were more-likely to be lost. Among subjects followed, the likelihood of working or being in school 1 year after discharge was significantly less for those intoxicated at time of injury and those with a history of substance abuse.
Systematic bias in longitudinal studies may result from subjects with substance use problems being lost to follow-up. Population estimates for return to work or school will be overestimated if those lost who have substance use problems resemble those followed.
（1）研究创伤性脑损伤患者样本中在1年随访时失访的受试者所产生的系统偏差；（2）确定结果数据推广的潜在威胁。
对急性康复出院后1年进行研究的连续入院样本。
一家大型学术医疗中心的住院脑损伤康复科。
88例原发性创伤性脑损伤患者。
当通过电话、邮件、门诊就诊以及家人协助仍无法在急性康复出院1年后取得联系时，受试者被视为失访。针对七个次优结果检查了有偏差的随访样本的潜在影响。
共有38.6%的受试者失访。受伤时醉酒的受试者以及有药物滥用史的受试者更有可能失访。在接受随访的受试者中，受伤时醉酒的受试者以及有药物滥用史的受试者在出院1年后工作或上学的可能性显著较低。
纵向研究中的系统偏差可能源于有物质使用问题的受试者失访。如果有物质使用问题的失访者与接受随访者相似，那么对重返工作或学校的人群估计将会被高估。
