Parry Emma, Ogollah Reuben, Peat George
NIHR In-Practice Fellow, Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK.
Research Fellow in Biostatistics, Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Keele, ST5 5BG, Staffordshire, UK.
BMC Musculoskelet Disord. 2017 Feb 14;18(1):80. doi: 10.1186/s12891-017-1434-3.
While knee osteoarthritis (OA) is characterised as a slowly progressive disease, acute flares, episodes of severe pain, and substantial fluctuations in pain intensity appear to be part of the natural history for some patients. We sought to estimate what proportion of symptomatic community-dwelling adults might be affected, and to identify patient and problem characteristics associated with higher risk of such variability in pain.
We analysed data collected at baseline, 18, 36, 54, and 72 month follow-up of a prospective cohort of symptomatic adults aged over 50 years with current/recent knee pain. At each time point we estimated the proportion of participants reporting 'significant pain variability' (defined as worst pain intensity in the past 6 months ≥5/10 and ≥2 points higher than average pain intensity during the same 6-month period). The associations between significant pain variability and demographic, socioeconomic, lifestyle, clinical, radiographic, and healthcare utilisation factors measured at baseline were estimated by adjusted odds ratios and 95% confidence intervals (aOR; 95%CI) from multivariable discrete-time survival analysis.
Seven hundred and nineteen participants were included in the final analysis. At each time point, 23-32% of participants were classed as reporting significant pain variability. Associated factors included: younger age (aOR (per year): 0.96; 95% CI 0.94, 0.97), higher BMI (per kg/m:1.03; 1.01, 1.06), higher WOMAC Pain score (per unit: 1.06; 1.03, 1.10), longer time since onset (e.g. 1-5 years vs < 1 year: 1.79; 1.16, 2.75) and morning stiffness (≤30 min vs none: 1.43; 1.10, 1.85). The models accounting for multiple periods of significant symptom variability found similar associations.
Our findings are consistent with studies showing that, for some patients OA symptoms are significantly variable over time. Future prospective studies on the nature and frequency of flare ups are needed to help determine triggers and their underlying pathophysiology in order to suggest new avenues for effective episode management of OA to complement long-term behaviour change.
虽然膝关节骨关节炎（OA）被认为是一种缓慢进展的疾病，但急性发作、严重疼痛发作以及疼痛强度的大幅波动似乎是部分患者自然病程的一部分。我们试图估算有症状的社区居住成年人中可能受影响的比例，并确定与疼痛这种变异性风险较高相关的患者和问题特征。
我们分析了对50岁以上有当前/近期膝关节疼痛的有症状成年人前瞻性队列在基线、18、36、54和72个月随访时收集的数据。在每个时间点，我们估算报告“显著疼痛变异性”（定义为过去6个月中最严重疼痛强度≥5/10且比同一6个月期间平均疼痛强度高≥2分）的参与者比例。通过多变量离散时间生存分析的调整比值比和95%置信区间（aOR；95%CI）估算基线时测量的显著疼痛变异性与人口统计学、社会经济、生活方式、临床、影像学和医疗保健利用因素之间的关联。
719名参与者纳入最终分析。在每个时间点，23 - 32%的参与者被归类为报告有显著疼痛变异性。相关因素包括：年龄较小（aOR（每年）：0.96；95%CI 0.94，0.97）、较高的体重指数（每kg/m²：1.03；1.01，1.06）、较高的WOMAC疼痛评分（每单位：1.06；1.03，1.10）、发病后时间较长（例如1 - 5年与<1年：1.79；1.16，2.75）以及晨僵（≤30分钟与无晨僵：1.43；1.10，1.85）。考虑多个显著症状变异性时期的模型发现了类似的关联。
我们的研究结果与表明对于一些患者OA症状随时间显著变化的研究一致。未来需要对发作的性质和频率进行前瞻性研究，以帮助确定触发因素及其潜在病理生理学，从而为OA有效发作管理提出新途径，以补充长期行为改变。
