The Shoulder Pain and Disability Index demonstrates factor, construct and longitudinal validity.

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Health Outcomes Measurement

Background:

• The Shoulder Pain and Disability Index (SPADI) is a widely used self-report measure for shoulder pathology.
• Previous validation studies exist, but broader analyses are needed to confirm its utility.
• This study aimed to assess the cross-sectional and longitudinal validity of the SPADI.

Purpose of the Study:

• To determine the cross-sectional and longitudinal validity of the Shoulder Pain and Disability Index (SPADI).
• To evaluate the SPADI's reliability and its correlation with other measures of pain and disability.
• To confirm the SPADI's suitability for assessing patients with musculoskeletal shoulder pain.

Main Methods:

• 129 community volunteers with self-identified shoulder pain underwent physical therapist examination.
• Patients completed the SPADI, Coping Strategies Questionnaire (CSQ), and Sickness Impact Profile (SIP) at baseline, 3, and 6 months.
• Factor analysis and Pearson correlations were used to assess construct validity, convergent/divergent validity, and longitudinal changes.

Main Results:

• The SPADI demonstrated high internal consistency (alpha > 0.92) and factor analysis confirmed pain and disability as primary factors.
• SPADI scores correlated with coping strategies (CSQ) and pain intensity (VAS), supporting convergent validity.
• Hypotheses regarding diagnosis and pain medication use were supported, and the SPADI showed significant changes over time.

Conclusions:

• The SPADI is a reliable and valid instrument for assessing pain and disability in community-based patients with musculoskeletal shoulder conditions.
• The findings support the use of the SPADI as a primary outcome measure in clinical practice and research.
• The SPADI effectively captures changes in shoulder pain and disability over time.