Damen Nikki L, Versteeg Henneke, Serruys Patrick W, van Geuns Robert-Jan M, van Domburg Ron T, Pedersen Susanne S, Boersma Eric
Tilburg University, Tilburg, The Netherlands.
Erasmus MC, Rotterdam, The Netherlands.
Eur J Prev Cardiol. 2015 Feb;22(2):196-9. doi: 10.1177/2047487313506548. Epub 2013 Sep 24.
Non-response is a serious threat to the external validity of longitudinal psychosocial studies. Little is known about potential systematic differences between patients with coronary artery disease who complete a psychosocial study and those who drop out prematurely due to non-response, or whether drop-outs may have a different cardiovascular risk. We studied a cohort of 1132 consecutive patients undergoing percutaneous coronary intervention (PCI). At baseline, all patients completed the Hospital Anxiety and Depression Scale (HADS) and the Type D Scale (DS14). At 12 months follow-up, 70.8% (n = 802) of patients completed both questionnaires, while 29.2% (n = 330) dropped out. We observed significant differences in socio-demographic, clinical, and psychological baseline characteristics between completers and drop-outs. Drop-outs were younger, more likely to smoke, but less often prescribed cardiovascular medications, including calcium antagonists and angiotensin-converting enzyme inhibitors, as compared with completers. Drop-outs more often had depression, anxiety, and negative affectivity, as compared with completers (all p-values <0.05). After a median follow-up of 4 years, we found no significant differences in mortality risk between completers and drop-outs (6.5 vs. 7.3%; adjusted HR 1.34, 95% CI 0.82-2.19, respectively). In conclusion, a possible attrition bias occurred, as drop-outs and completers differed systematically on some socio-demographic, clinical, and psychological baseline characteristics. Despite these differences, this did not translate into a poorer short-term prognosis, as there were no differences in the mortality risk of completers vs. drop-outs after a median follow-up of 4 years. In future prospective studies, attention should be paid to attrition bias, and its possible impact on study results and implications should be discussed.
无应答是纵向社会心理研究外部效度的严重威胁。对于完成社会心理研究的冠心病患者与因无应答而提前退出研究的患者之间潜在的系统差异，或者退出者是否可能有不同的心血管风险，我们知之甚少。我们研究了连续接受经皮冠状动脉介入治疗（PCI）的1132例患者队列。在基线时，所有患者均完成了医院焦虑抑郁量表（HADS）和D型量表（DS14）。在12个月的随访中，70.8%（n = 802）的患者完成了两份问卷，而29.2%（n = 330）的患者退出。我们观察到完成者和退出者在社会人口统计学、临床和心理基线特征方面存在显著差异。与完成者相比，退出者更年轻，吸烟可能性更大，但较少被开具心血管药物，包括钙拮抗剂和血管紧张素转换酶抑制剂。与完成者相比，退出者更常出现抑郁、焦虑和负性情感（所有p值<0.05）。在中位随访4年后，我们发现完成者和退出者在死亡风险方面无显著差异（分别为6.5%和7.3%；调整后HR为1.34，95%CI为0.82 - 2.19）。总之，可能存在失访偏倚，因为退出者和完成者在一些社会人口统计学、临床和心理基线特征上存在系统差异。尽管存在这些差异，但这并未转化为更差的短期预后，因为在中位随访4年后，完成者与退出者的死亡风险并无差异。在未来的前瞻性研究中，应注意失访偏倚，并应讨论其对研究结果和影响的可能作用。
