Cooney T M, Schaie K W, Willis S L
Pennsylvania State University, University Park 16802.
J Gerontol. 1988 Jan;43(1):P12-7. doi: 10.1093/geronj/43.1.p12.
This study compared the intellectual and personality functioning of continuing participants in a longitudinal study with individuals who were lost from the panel after at least 7 years of involvement. Based on their reason for discontinuation, participants who were lost to the panel were categorized into three attrition groups: deceased, ill, and voluntary dropouts. When the performance of these groups prior to leaving the study was compared with that of the continuing participants, no general differences were found. However, specific differences were revealed, particularly on crystallized-type intellectual abilities and the personality factors. Participants who were lost due to illness or death had functioned at the lowest levels of the four groups prior to attrition. These effects varied by age. In late middle age, ill participants functioned at the lowest levels, whereas in old age, participants who subsequently died scored lowest of the four groups prior to attrition. Individuals who had voluntarily discontinued participation in the study most closely resembled the continuing participants, particularly in late middle age. The results indicate that performance effects associated with continued participation vary by age, the intelligence or personality factor being considered, and the reason for loss of the participant. Furthermore, they suggest that loss of participants from a longitudinal panel does not inevitably bias the validity of developmental findings.
本研究比较了一项纵向研究中持续参与的参与者与参与至少7年后从样本中流失的个体的智力和人格功能。根据退出原因，从样本中流失的参与者被分为三个损耗组：死亡、患病和自愿退出。将这些组在离开研究之前的表现与持续参与的参与者的表现进行比较时，未发现总体差异。然而，发现了一些具体差异，特别是在晶态智力能力和人格因素方面。因病或死亡而流失的参与者在损耗前的四个组中功能水平最低。这些影响因年龄而异。在中年后期，患病参与者的功能水平最低，而在老年，随后死亡的参与者在损耗前的四个组中得分最低。自愿停止参与研究的个体与持续参与的参与者最为相似，尤其是在中年后期。结果表明，与持续参与相关的表现影响因年龄、所考虑的智力或人格因素以及参与者流失的原因而异。此外，研究结果表明，纵向样本中参与者的流失并不一定会使发展研究结果的有效性产生偏差。
