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Table 2 Weighting schemes

From: Inter-rater reliability of the QuIS as an assessment of the quality of staff-inpatient interactions

Weighting scheme   + s + c N - p - r COMMENTS
Unweighted + social 1      Ignores the degree of misclassification between categories
+ care 0 1    
Neutral 0 0 1   
- protective 0 0 0 1  
- restrictive 0 0 0 0 1
Linear + social 1      Standard weights 1 for ordinal variables in Stata. Weights 1-|i-j|/(k-1), where i and j index the rows and columns, and k the number of categories
+ care 1 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 1 1
Quadratic + social 1      Standard weights 2 for ordinal variables in Stata. Weights 1 - {(i-j)/(k-1)}2.
+ care 0.75 1    
Neutral 0.5 0.75 1   
- protective 0.25 0.5 0.75 1  
- restrictive 0 0.25 0.5 0.75 1
A: Weights given to neutral compared to a positive or negative = 0.5, assuming that misclassification between the positives is equal to misclassification between the negatives.
Weighted A1 + social 1      All possibilities from weighting misclassification between the two positives and the two negatives as 1 (will be the same as having only three categories, positive neutral and negative) to weighting it as 0.6. Weighting scheme 4 has a weights of 0.75 (half way between .5 and 1)
+ care 1 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 1 1
Weighted A2 + social 1     
+ care 0.9 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.9 1
Weighted A3 + social 1     
+ care 0.8 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.8 1
Weighted A4 + social 1     
+ care 0.75 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.75 1
Weighted A5 + social 1     
+ care 0.7 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.7 1
Weighted A6 + social 1     
+ care 0.6 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.6 1
Weighting scheme   + s + c N - p - r COMMENTS
B: Weights using less than 0.5 for neutral compared to a positive or negative and assuming that misclassification between the two positives is equal to misclassification between the two negatives
Weighted B1 + social 1      
+ care 0.66 1     
Neutral 0.33 0.33 1   
- protective 0 0 0.33 1  
- restrictive 0 0 0.33 0.66 1
Weighted B2 + social 1      
+ care 0.5 1    
Neutral 0.25 0.25 1   
- protective 0 0 0.25 1  
- restrictive 0 0 0.25 0.5 1
Weighted B3 + social 1      
+ care 0.5 1    
Neutral 0 0 1   
- protective 0 0 0 1  
- restrictive 0 0 0 0.5 1  
C: Weights assuming that misclassification between the two negative categories is less important than misclassification between the two positives and varying the neutral weights
Weighted C1 + social 1      
+ care 0.5 1    
Neutral 0.25 0.25 1   
- protective 0 0 0.25 1  
- restrictive 0 0 0.25 0.75 1
Weighted C2 + social 1     
+ care 0.6 1    
Neutral 0.4 0.4 1   
- protective 0 0 0.4 1  
- restrictive 0 0 0.4 0.8 1
Weighted C3 + social 1     
+ care 0.66 1    
Neutral 0.5 0.5 1   
- protective 0 0 0.5 1  
- restrictive 0 0 0.5 0.83 1