Exploratory Study of 6-Month Pain Trajectories in Individuals With Predominant Patellofemoral Osteoarthritis: A Cohort Study

Identifying multiple knee pain trajectories and the prediction of opioid and NSAID medication used: A latent class growth approach

BACKGROUND

Knee pain is a major source of distress and disability, with pain progression highly variable between individuals. Previous studies defining pain trajectories have all used a single measure of pain, and these differ across studies. Different measures reflect diverse pain mechanisms. To ascertain the clinical utility of pain trajectories, we explored associations between opioid and non-steroidal anti-inflammatory drug (NSAID) use.

METHODS

We model pain trajectories using two measures-Intermittent and Constant Osteoarthritis Pain (ICOAP) and the painDETECT, in 2141 participants, across 3 waves (the baseline, 1- and 3-year assessments) of the Knee Pain In the Community (KPIC) cohort.

RESULTS

Latent class growth analysis identified six trajectories using ICOAP subscales (High-Stable, Low-Stable, Moderate Worsening, Moderate Recovering, Worsening, and Recovering) and four trajectories using painDETECT (High-stable, Low-stable, Moderate Worsening, and Moderate Recovering). There was a high degree of correspondence between people assigned to pain trajectories between ICOAP intermittent and constant subscales, but less so using painDETECT. Opioid use was associated with ICOAP trajectories only (e.g., High-Stable and Worsening intermittent ICOAP trajectories) and in women.

CONCLUSION

Different measures of pain produce different patterns of pain progression and these are differentially related to medication use. Opioid use is linked to trajectories of pain based on the impact of pain on behavior and not pain symptoms. Thus, managing pain's behavioral impact is more central to understanding opioid use than managing pain symptoms. These findings support more in-depth questioning about the type of pain and its progression in clinical practice.

Fear Avoidance Predicts Persistent Pain in Young Adults With Low Back Pain: A Prospective Study

OBJECTIVES

To (1) quantify relationships between low back pain (LBP) symptoms, physical activity, and psychosocial characteristics in young adults and (2) identify subclasses of young adults with distinct pain trajectories.

DESIGN

Prospective cohort study with 12-month follow-up.

METHODS

One hundred twenty adults (mean ± SD age, 20.8 ± 2.6 years; 99 women) participated. Participants completed a baseline survey that measured anxiety, depression, fear avoidance, quality of life, and history and impact of any LBP. Participants completed follow-up surveys every 3 months for 1 year. Subclasses based on pain trajectories over time were identified using latent class analysis, and predictors of class membership at baseline were assessed.

RESULTS

Individuals with LBP at baseline had lower physical quality-of-life scores than back-healthy participants (P = .01). Subclass 1 (25% of individuals with LBP) had persistent moderate-to-high pain intensity over the 1-year study period. Subclass 2 (75% of individuals with LBP) had significantly improving pain over the 1-year study period. Higher fear avoidance (physical activity subscale) and pain interference at baseline were associated with greater odds of membership in subclass 1 (odds ratio = 1.2; 95% confidence interval: 1.0, 1.3 and odds ratio = 1.4; 95% confidence interval: 1.1, 1.6, respectively).

CONCLUSION

Most young adults with LBP had symptoms that improved over time. Levels of fear avoidance and pain interference may help to identify individuals at risk of persistent pain early in the lifespan. J Orthop Sports Phys Ther 2021;51(8):383-391. Epub 15 May 2021. doi:10.2519/jospt.2021.9828.

Knee pain trajectories over 18 months in non-Hispanic Black and non-Hispanic White adults with or at risk for knee osteoarthritis

BACKGROUND

Pain is the hallmark symptom of knee osteoarthritis (OA), and varies widely across individuals. Previous research has demonstrated both fluctuating and stable pain trajectories in knee OA using various time periods. Changes in pain assessed quarterly (i.e. 3-month intervals) in knee OA are relatively unknown. The current study aimed to investigate temporal variations in pain over a one and a half year period (18 months) based on quarterly characteristic pain assessments, and to examine differences in pain patterns by sociodemographic and baseline pain characteristics.

METHODS

The sample included a prospective cohort of 188 participants (mean age 58 years; 63% female; 52% non-Hispanic Black) with or at risk for knee OA from an ongoing multisite investigation of ethnic/race group differences. Knee pain intensity was self-reported at baseline and quarterly over an18-month period. Baseline pain assessment also included frequency, duration, and total number of pain sites. Group-based trajectory modeling was used to identify distinct pain trajectories. Multinomial logistic regression was used to examine associations between sociodemographic characteristics, risk factors, and pain trajectory groups.

RESULTS

Pain trajectories were relatively stable among a sample of adults with knee pain. Four distinct pain trajectories emerged in the overall sample, with the largest proportion of participants (35.1%) classified in the moderate-high pain group. There were significant relationships between age, education, income, ethnicity/race and trajectory group; with younger, less educated, lower income, and non-Hispanic Black participants had a greater representation in the highest pain trajectory group.

CONCLUSIONS

Pain remained stable across a one and a half-year period in adults with or at risk for knee osteoarthritis, based on quarterly assessments. Certain sociodemographic variables (e.g. ethnicity/race, education, income, age) may contribute to an increased risk of experiencing greater pain.

What Have We Learned From Trajectory Analysis of Clinical Outcomes in Knee and Hip Osteoarthritis Before Surgery?

OBJECTIVE

The past decade has seen a rapid increase in the publication of studies using trajectory analysis to describe the course of osteoarthritis (OA) symptoms. The aim of this systematic review was to describe the distinct trajectories for OA outcomes and the predictors of these trajectories.

METHODS

Medline and PsycInfo databases were searched for relevant studies. Selection criteria were 1) patients ≥18 years of age, 2) patients at high risk of or diagnosed with knee or hip OA, 3) studies aiming to identify homogeneous subgroups with distinct trajectories of clinical outcomes, and 4) methodology and analysis designed to identify trajectories (longitudinal design and repeated measures). The search was limited to publications in English or French.

RESULTS

Of the 5,177 abstracts retrieved, 44 studies met the inclusion criteria; 21 described the disease progression before surgery. The most frequent outcomes were pain and physical function. Up to 6 trajectories of pain were found for hip and knee OA. For function, between 1 and 5 trajectories were identified for knee OA. Low educational level, high body mass index, and high number of comorbidities were the most reported predictors of bad evolution.

CONCLUSION

Although studies were heterogeneous (outcome, subgroup number, and composition), they revealed stable OA trajectories over time. This finding suggests that OA is a chronic disease that does not inevitably worsen in terms of patient-reported symptoms.