The Nordic Maintenance Care Program: Does psychological profile modify the treatment effect of a preventive manual therapy intervention? A secondary analysis of a pragmatic randomized controlled trial

BackgroundChiropractic maintenance care is effective as secondary/tertiary prevention of non-specific low back pain (LBP), but the potential effect moderation by psychological characteristics is unknown. The objective was to investigate whether patients in specific psychological sub-groups had different responses to MC with regard to the total number of days with bothersome pain and the number of treatments.MethodData from a two-arm randomized pragmatic multicenter trial with a 12-month follow up, designed to investigate the effectiveness of maintenance care, was used. Consecutive patients, 18–65 years of age, with recurrent and persistent LBP seeking chiropractic care with a good effect of the initial treatment were included. Eligible subjects were randomized to either maintenance care (prescheduled care) or to the control intervention, symptom-guided care. The primary outcome of the trial was the total number of days with bothersome LBP collected weekly for 12 months using an automated SMS system. Data used to classify patients according to psychological subgroups defined by the West Haven-Yale Multidimensional Pain Inventory (adaptive copers, interpersonally distressed and dysfunctional) were collected at the screening visit.ResultsA total of 252 subjects were analyzed using a generalized estimating equations linear regression framework. Patients in the dysfunctional subgroup who received maintenance care reported fewer days with pain (-30.0; 95% CI: -36.6, -23.4) and equal number of treatments compared to the control intervention. In the adaptive coper subgroup, patients who received maintenance care reported more days with pain (10.7; 95% CI: 4.0, 17.5) and more treatments (3.9; 95% CI: 3.5, 4.2). Patients in the interpersonally distressed subgroup reported equal number of days with pain (-0.3; 95% CI: -8.7, 8.1) and more treatments (1.5; 95% CI: 0.9, 2.1) on maintenance care.ConclusionsPsychological and behavioral characteristics modify the effect of MC and should be considered when recommending long-term preventive management of patients with recurrent and persistent LBP.

研究背景：脊椎按摩维持治疗（Chiropractic maintenance care）可作为非特异性下腰痛（non-specific low back pain, LBP）的二级/三级预防手段，但心理特征对其效应的潜在调节作用尚不明确。本研究旨在探究不同心理亚组患者接受维持治疗后，在困扰性疼痛总天数与治疗次数方面是否存在不同的应答效果。
研究方法：本研究采用一项旨在评估维持治疗有效性的双臂随机实用多中心试验数据，随访时长为12个月。研究纳入年龄18~65岁、复发性持续性非特异性下腰痛且初始脊椎按摩治疗效果良好的连续就诊患者。符合入组标准的受试者被随机分配至维持治疗组（按计划接受治疗）或对照组（症状引导式治疗）。本试验的主要结局指标为通过自动化短信系统每周收集12个月内的困扰性下腰痛总天数。筛查访视时收集受试者数据，以基于西黑文-耶鲁多维疼痛量表（West Haven-Yale Multidimensional Pain Inventory）划分的心理亚组（适应性应对者、人际困扰型、功能失调型）对患者进行分类。
研究结果：本研究共纳入252名受试者并采用广义估计方程线性回归框架进行分析。相较于对照组，功能失调型亚组中接受维持治疗的患者报告的疼痛困扰天数更少（-30.0；95%置信区间：-36.6~-23.4），且治疗次数无显著差异。适应性应对者亚组中，接受维持治疗的患者报告的疼痛困扰天数更多（10.7；95%置信区间：4.0~17.5），治疗次数也更多（3.9；95%置信区间：3.5~4.2）。人际困扰型亚组患者在维持治疗下的疼痛困扰天数无显著差异（-0.3；95%置信区间：-8.7~8.1），但治疗次数更多（1.5；95%置信区间：0.9~2.1）。
研究结论：心理与行为特征可调节维持治疗的效应，因此在为复发性持续性非特异性下腰痛患者推荐长期预防性管理方案时，应考虑患者的心理与行为特征。