Fig 1.
Flow of the experimental design.
Fig 2.
Timeline of the periods of observations used for pain scale validation.
Table 1.
The Unesp-Botucatu composite pain scale for assessing postoperative pain in piglets (UPAPS).
Table 2.
Statistical methods used for refinement (R) and validation (V) of the Unesp-Botucatu pig acute pain scale (UPAPS) in the piglets post-castration.
Fig 3.
Distribution of UPAPS items scores (percentage of occurrence) in castrated piglets (n = 39).
Legend: M1 (24h pre-procedure), M2 (15-min post-procedure, before rescue analgesia), M3 (3h post-procedure, after rescue analgesia), M4 (24h post-procedure) GM—data of the grouped moments (M1 + M2 + M3 + M4).
Fig 4.
Distribution of UPAPS items scores (percentage of occurrence) in awake castrated piglets (n = 14).
Legend: M1 (24h pre-procedure), M2 (15-min post-procedure, before rescue analgesia); GM—data of the grouped moments (M1 + M2).
Table 3.
Weighted kappa (kw) or intra-class correlation coefficient (ICC) and confidence interval of the 95% from inter-observer matrix agreement of each item and the sum of the UPAPS applied for all castrated piglets (n = 39) over all moments.
Fig 5.
Biplot of the principal component analysis of the UPAPS items applied to all castrated piglets (n = 39).
UPAPS–Unesp-Botucatu pig acute composite pain scale. Confidence ellipses indicate perioperative moments and pain scores. Moments: M1 (24h pre-procedure), M2 (15-min post-procedure, before rescue analgesia), M3 (3h post-procedure, after rescue analgesia), M4 (24h post-procedure). Ellipses were constructed according to the assessment. Each circle corresponds to the score from one observer attributed to each piglet at each moment.
Fig 6.
Biplot of the principal component analysis of the UPAPS items applied to awake piglets (n = 14 castrated piglets).
UPAPS–Unesp-Botucatu pig acute composite pain scale. Confidence ellipses indicate perioperative moments and pain scores. Moments: M1 (24h pre-procedure), M2 (15-min post-procedure, before rescue analgesia). Ellipses were constructed according to the assessment. Each circle corresponds to the score from one observer attributed to each piglet at each moment.
Table 4.
Loading values, eigenvalues and variance of the UPAPS items applied to castrated piglets (n = 39) and castrated piglets awake (n = 14) based on principal components analysis.
Table 5.
Item-total correlation of the UPAPS applied for all castrated piglets (n = 39).
Table 6.
Specificity and sensitivity and 95% confidence interval (CI) of the UPAPS applied for all castrated piglets (n = 39) and awake castrated piglets (n = 14).
Fig 7.
Violin plot of the total sum (median/amplitude) of the a) UPAPS (all castrated piglets; n = 39) and b) UPAPS (awake castrated piglets; n = 14) before and after castration in piglets.
The violin contour represents the dispersion of data density, with the wider contour representing greater data density. The top and bottom box lines represent the interquartile range (25 to 75%), the line within the box represents the median, the extremes of the whiskers represent the minimum and maximum values, black lozenges (♦) represent the mean, black circles (●) represent outliers. UPAPS: Unesp-Botucatu pig acute composite pain scale. Different letters express significant differences between moments where a > b > c, according to the generalized mixed linear models [27]. M1 (24h pre-procedure), M2 (15-min post-procedure, before rescue analgesia), M3 (3h post-procedure, after rescue analgesia), M4 (24h post-procedure).
Table 7.
Median (amplitude) of the UPAPS scores before and after castration in all castrated piglets (n = 39).
Fig 8.
Violin plot of the total sum (median/amplitude) of the a) UPAPS for castrated piglets (n = 14) and non-painful female piglets (n = 6) after castration (M2) and before rescue analgesia in piglets awake during the assessment.
The violin contour represents the dispersion of data density, with the wider contour representing greater data density. The top and bottom box lines represent the interquartile range (25 to 75%), the line within the box represents the median, the extremes of the whiskers represent the minimum and maximum values, black lozenges (♦) represent the mean, black circles (●) represent outliers. Sub-UPAPS: Unesp-Botucatu pig acute composite pain scale. Different letters express significant differences between moments where a > b > c, according to the generalized mixed linear models [27]. M2 (15-min post-procedure, before rescue analgesia).
Table 8.
Median (amplitude) of the UPAPS scores before and after castration in castrated piglets awake (n = 14) during the assessment.
Table 9.
Median (amplitude) of the UPAPS scores for castrated (n = 14) and non-painful female piglets (n = 6) awake piglets at M2.
Table 10.
Internal consistency of the UPAPS applied for castrated piglets awake (n = 14).
Fig 9.
Receiver Operating Characteristic (ROC) curve and area under the curve (AUC) of the UPAPS applied to castrated piglets awake (n = 14).
AUC values above 0.90 represent high discriminatory capacity (accuracy) of the scale [37]. The gray region represents the 95% confidence interval.
Table 11.
Specificity, sensitivity, and Youden index of optimal cut-off for UPAPS.