# Subjective Happiness Scale: Measurement properties of the online and paper-pen administrations in Nepali adults with musculoskeletal pain

## TL;DR

The study validates the Subjective Happiness Scale for measuring happiness in Nepali adults with musculoskeletal pain, showing it works well in both paper and online formats.

## Contribution

The study confirms the SHS's validity and reliability in Nepali adults with musculoskeletal pain and identifies item #4 as problematic.

## Key findings

- The SHS demonstrated a single factor structure and good internal consistency across all administration methods.
- Test-retest reliability was moderate to good for combined and hard-copy samples but lower for online.
- Construct validity was supported for both online and paper-based administrations.

## Abstract

Happiness is a positive psychological construct often described as subjective well-being. It is associated with a meaningful life, and better social support and coping with stress or trauma. Happiness may have a role in buffering the negative effects of musculoskeletal pain on quality of life. Validating measures that assess subjective happiness in individuals with musculoskeletal pain can help advance research and patient care in this emerging field.

We sought to: (1) evaluate the measurement properties of the Subjective Happiness Scale (SHS) in a sample of Nepali adults with musculoskeletal pain; and (2) compare its measurement properties when administered using hard-copy and online methods.

The Consensus-based Standards for the selection of health status Measurement Instruments (COSMIN) guidelines informed the conduct and reporting. A total of 180 (120 hard-copy and 60 online administrations) individuals with musculoskeletal pain were recruited in Nepal. Content validity, structural validity (exploratory factor analysis), internal consistency (Cronbach’s alpha), construct validity (hypothesis testing), and test-retest reliability (Intraclass Correlation Coefficient, ICC2,1), measurement error were assessed.

Single factor structure of the SHS was supported. The SHS showed good internal consistency for the combined, hard-copy, and online samples (Cronbach’s alphas 0.857, 0.848, and 0.847, respectively). It evidenced moderate to good test-retest reliability [ICCs = 0.86 (95 % CI: 0.80, 0.93), 0.89 (95 % CI: 0.82, 0.93), and 0.66 (95 % CI: 0.32, 0.87), respectively]. The findings also supported the construct validity for both administration types.

This study supports the validity of the SHS for assessing subjective happiness in adults with musculoskeletal pain, with moderate to good reliability.

•Happiness may be an important protective factor in musculoskeletal pain.•Nepali Subjective Happiness Scale (SHS-NP) has one factor solution.•Item #4 was incomprehensible by Nepali adults.•SHS-NP is reliable and valid tool to assess subjective happiness.•Responsiveness and minimum important change needs further testing.

Happiness may be an important protective factor in musculoskeletal pain.

Nepali Subjective Happiness Scale (SHS-NP) has one factor solution.

Item #4 was incomprehensible by Nepali adults.

SHS-NP is reliable and valid tool to assess subjective happiness.

Responsiveness and minimum important change needs further testing.