BACKGROUND: Minimal clinically important difference (MCID) is the smallest change in an outcome, which a patient identifies as meaningful. Although the 2 most frequently applied Parkinson's disease (PD) "quality of life" questionnaires (the PDQ-39 and PDQ-8) provide encouragingly similar results, their MCID thresholds appear to be vastly different. Our aim was to calculate the MCID estimates for both PDQ-39 and PDQ-8 Summary Indices (PDQ-39-SI and PDQ-8-SI) by the utilization of both anchor- and distribution-based techniques. METHODS: Nine hundred eighty-five paired investigations of 365 patients were included. Three different techniques were used simultaneously to calculate the MCID values. RESULTS: First, we replicated the previously published results demonstrating how both PDQ-39-SI and PDQ-8-SI provide similar values and respond in a similar way to changes. Subsequently, we calculated the MCID thresholds. The most optimal estimates for MCID thresholds for PDQ-39-SI were -4.72 and +4.22 for detecting minimal clinically important improvement and worsening. For PDQ-8-SI, these estimates were -5.94 and +4.91 points for detecting minimal clinically important improvement and worsening respectively. CONCLUSIONS: Our study is the first one that directly compared the MCID estimates for both PDQ-39-SI and PDQ-8-SI on a large pool of patients including all disease severity stages. These MICD estimates varied across PD severity.
BACKGROUND: Minimal clinically important difference (MCID) is the smallest change in an outcome, which a patient identifies as meaningful. Although the 2 most frequently applied Parkinson's disease (PD) "quality of life" questionnaires (the PDQ-39 and PDQ-8) provide encouragingly similar results, their MCID thresholds appear to be vastly different. Our aim was to calculate the MCID estimates for both PDQ-39 and PDQ-8 Summary Indices (PDQ-39-SI and PDQ-8-SI) by the utilization of both anchor- and distribution-based techniques. METHODS: Nine hundred eighty-five paired investigations of 365 patients were included. Three different techniques were used simultaneously to calculate the MCID values. RESULTS: First, we replicated the previously published results demonstrating how both PDQ-39-SI and PDQ-8-SI provide similar values and respond in a similar way to changes. Subsequently, we calculated the MCID thresholds. The most optimal estimates for MCID thresholds for PDQ-39-SI were -4.72 and +4.22 for detecting minimal clinically important improvement and worsening. For PDQ-8-SI, these estimates were -5.94 and +4.91 points for detecting minimal clinically important improvement and worsening respectively. CONCLUSIONS: Our study is the first one that directly compared the MCID estimates for both PDQ-39-SI and PDQ-8-SI on a large pool of patients including all disease severity stages. These MICD estimates varied across PD severity.
Authors: Dongni Johansson; Anders Ericsson; Anders Johansson; Alexander Medvedev; Dag Nyholm; Fredrik Ohlsson; Marina Senek; Jack Spira; Ilias Thomas; Jerker Westin; Filip Bergquist Journal: CNS Neurosci Ther Date: 2018-01-25 Impact factor: 5.243
Authors: Caroline A Mulvaney; Gonçalo S Duarte; Joel Handley; David Jw Evans; Suresh Menon; Richard Wyse; Hedley Ca Emsley Journal: Cochrane Database Syst Rev Date: 2020-07-23
Authors: Linda Tickle-Degnen; Michael T Stevenson; Sarah D Gunnery; Marie Saint-Hilaire; Cathi A Thomas; Linda Sprague Martinez; Barbara Habermann; Elena N Naumova Journal: Disabil Rehabil Date: 2020-04-01 Impact factor: 3.033