Physical dysfunction and nonorganic signs in patients with chronic neck pain: exploratory study into interobserver...

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Pain Management

Background:

• The Physical Dysfunction Severity (PDS) scale aids in evaluating treatment efficacy for neck pain.
• Cervical nonorganic signs (NOS) were developed to assess illness behavior in patients with neck pain.

Purpose of the Study:

• To evaluate the interobserver reliability of the modified Physical Dysfunction Severity (mPDS) scale for cervical spine impairment.
• To assess the interobserver reliability of the modified Cervical Nonorganic Signs (mcNOS) for behavioral signs.
• To explore the construct validity of both the mPDS and mcNOS.

Main Methods:

• A repeated-measurement design was employed.
• Two independent observers assessed 51 chronic neck pain patients using the mPDS and mcNOS.
• Interobserver reliability was determined using intraclass correlation coefficients (ICC) and Cohen kappa; construct validity was assessed via Spearman correlation.

Main Results:

• The mPDS and mcNOS demonstrated acceptable interobserver reliability with ICCs of 0.72 and 0.78, respectively.
• Individual mcNOS test agreement ranged from 63% to 88% (kappa: 0.14–0.54), indicating poor to acceptable agreement.
• Construct validity was satisfactory, with correlations ranging from 0.26 to 0.49 with established neck pain scales.

Conclusions:

• Both the mPDS and mcNOS exhibit acceptable interobserver reliability for assessing chronic neck pain.
• While overall reliability is good, agreement on individual mcNOS tests varies.
• The construct validity of the mPDS and mcNOS suggests they are suitable measures for clinical use.