Psychometric features of brief pain inventory for Parkinson's disease during medication states.

The BPI has acceptable psychometric features as well as diagnostic accuracy for patients with PD.Implications for rehabilitationPain as a non-motor symptom in PD can affect daily and social activities.The BPI is used to assess pain severity and interference in activities.For better treatment, pain should be assessed in off-state like to on-state.BPI has satisfactory reliability and validity in different medication states in PD.