Measurement properties of the Arabic Leeds Assessment of Neuropathic Symptoms and Signs (A-LANSS) pain scale: A secondary analysis

Osama Tashani1, 2 , Sabri Garoushi1,2,3, Ghazala Tabasam1,2 and Mark I. Johnson1,2

1Centre for Pain Research, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK. 2MENA Research Group, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK. 3University of Benghazi, Benghazi, Libya

Background 
We have previously tested the concurrent validity, test-retest reliability and internal consistency of the A-LANSS pain scale (Garoushi et al. 2017). The aim of this study was to investigate the measurement properties of A-LANSS. 

Methods
One hundred and nine individuals with diabetes and attending the Benghazi Diabetic Centre, Libya completed the A-LANSS. Responses were analysed using to determine how many dimensions (constructs) the A-LANSS measured (exploratory factor analysis); convergent validity (correlation between A-LANSS score and a related variable, i.e. numerical pain scale); discriminant validity (correlation between A-LANSS score and an unrelated variable, i.e. age); and sensitivity, specificity AND predictive values were used to determine the ability of A-LANSS to distinguish between individuals with and without probable neuropathic pain when compared with clinical diagnosis. 

Results
The A-LANSS was composed of one factor (unidimensional) in accordance with the original LANSS. Convergent validity was high (r = 0.89, p = 0.0001), discriminant validity was acceptable (r = 0.235, p = 0.014), sensitivity was 88.6% and specificity was 81.1%. The positive predictive value was 68.9% and the negative predictive value 93.8%. Thirty-one of 35 (89%) individuals clinically diagnosed with PDN scored >12 on A-LANSS (i.e. probable neuropathic pain) compared with 14 of 79 (19%) individuals clinically diagnosed as not having PDN (z = 47.5, p = 0.0001).

Conclusion
The measurement properties of the A-LANSS were satisfactory and suggest utility as a screening tool for PDN in Arabic speaking populations.

MEASUREMENT PROPERTIES OF THE ARABIC LEEDS ASSESSMENT OF NEUROPATHIC SYMPTOMS AND SIGNS (A-LANSS) PAIN SCALE: A SECONDARY ANALYSIS