The aim of this study was to identify predictive factors for higher conversion ratio in
opioid switching from oral
oxycodone to transdermal
fentanyl (TDF) in patients with
cancer pain. The participants of this study were 156 hospitalized
cancer patients who underwent
opioid switching from oral
oxycodone to TDF at the Affiliated Hospital of Binzhou Medical University between January 1st, 2010 and March 31st, 2014. Patient characteristics, modified Glasgow Prognostic Score (mGPS), daily
oxycodone dose, and reasons for
opioid switching were retrospectively collected. The effect of variables on the conversion ratio was analyzed by multiple regression analysis to identify the predictive factors for higher conversion ratio in
opioid switching from oral
oxycodone to TDF. The results showed that the mGPS (odds ratio [OR], 2.358; 95% CI 1.379-4.031; P = 0.002), the reason for
opioid switching (OR, 0.497; 95% CI, 0.298-0.828; P = 0.007) and equivalent oral
morphine dose (OR, 1.700; 95% CI, 1.008-2.867; P = 0.046) were found to be significant predictors requiring higher conversion ratio in
opioid switching. This study indicates that higher mGPS, poor
pain control before switching and higher equivalent oral
morphine dose are significant predictors of a need for higher conversion ratio in
opioid switching from oral
oxycodone to TDF. These results could contribute to the establishment of evidence-based medicine in
cancer pain relief.