Integrative Spinal Research, Department of Chiropractic Medicine, University Hospital Balgrist, Forchstr. 340, 8008, Zurich, Switzerland.
Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 270, 8057, Zurich, Switzerland.
BMC Musculoskelet Disord. 2020 Aug 17;21(1):554. doi: 10.1186/s12891-020-03534-5.
Although mid back pain (MBP) is a common condition that causes significant disability, it has received little attention in research and knowledge about trajectories and prognosis of MBP is limited. The purpose of this study was to identify trajectories of MBP and baseline risk factors for an unfavorable outcome in MBP patients undergoing chiropractic treatment.
This prospective-observational study analyzes outcome data of 90 adult MBP patients (mean age = 37.0 ± 14.6 years; 49 females) during one year (at baseline, after 1 week, 1 month, 3, 6 and 12 months) after start of chiropractic treatment. Patients completed an 11-point (0 to 10) numeric pain rating scale (NRS) at baseline and one week, one month, three, six and twelve months after treatment start and the Patient's Global Impression of Change (PGIC) questionnaire at all time points except baseline. To determine trajectories, clustering with the package kml (software R), a variant of k-means clustering adapted for longitudinal data, was performed using the NRS-data. The identified NRS-clusters and PGIC data after three months were tested for association with baseline variables using univariable logistic regression analyses, conditional inference trees and random forest plots.
Two distinct NRS-clusters indicating a favourable (rapid improvement within one month from moderate pain to persistent minor pain or recovery after one year, 80% of patients) and an unfavourable trajectory (persistent moderate to severe pain, 20% of patients) were identified. Chronic (> 3 months) pain duration at baseline significantly predicted that a patient was less likely to follow a favourable trajectory [OR = 0.16, 95% CI = 0.05-0.50, p = 0.002] and to report subjective improvement after twelve months [OR = 0.19, 95% CI = 0.07-0.51, p = 0.001], which was confirmed by the conditional inference tree and the random forest analyses.
This prospective exploratory study identified two distinct MBP trajectories, representing a favourable and an unfavourable outcome over the course of one year after chiropractic treatment. Pain chronicity was the factor that influenced outcome measures using NRS or PGIC.
中背部疼痛（MBP）是一种常见的病症，会导致严重的残疾，但在研究中却很少受到关注，对 MBP 轨迹和预后的了解也很有限。本研究的目的是确定 MBP 患者接受脊医治疗后的轨迹，并确定基线时不利于 MBP 患者结局的危险因素。
这是一项前瞻性观察研究，分析了 90 名成年 MBP 患者（平均年龄 37.0±14.6 岁；49 名女性）在接受脊医治疗后一年（基线时、治疗后 1 周、1 个月、3 个月、6 个月和 12 个月）的结局数据。患者在基线时和治疗开始后 1 周、1 个月、3 个月、6 个月和 12 个月时，使用 11 分制（0 到 10）数字疼痛评分量表（NRS）进行评分，并在除基线外的所有时间点使用患者总体印象变化（PGIC）问卷进行评分。为了确定轨迹，使用软件 R 中的 kml 包（一种适用于纵向数据的 k-means 聚类的变体），使用 NRS 数据进行聚类。使用单变量逻辑回归分析、条件推理树和随机森林图，对 3 个月后确定的 NRS 聚类和 PGIC 数据与基线变量进行关联测试。
确定了两种不同的 NRS 聚类，表明存在有利（在一个月内从中度疼痛迅速改善为持续轻微疼痛或一年后恢复，80%的患者）和不利（持续中度至重度疼痛，20%的患者）的轨迹。基线时慢性（>3 个月）疼痛持续时间显著预示着患者不太可能出现有利的轨迹[比值比（OR）=0.16，95%置信区间（CI）=0.05-0.50，p=0.002]，并且在 12 个月后报告主观改善的可能性较低[OR=0.19，95%CI=0.07-0.51，p=0.001]，这一结果也得到了条件推理树和随机森林分析的证实。
这项前瞻性探索性研究确定了 MBP 在脊医治疗后一年的两种不同轨迹，代表了有利和不利的结局。疼痛的慢性是影响 NRS 或 PGIC 测量结果的因素。
