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Table 1 Simulated clinical record review (CRR) parameters and parameter values and their effect on the precision and power of harm rate estimates

From: Can we quantify harm in general practice records? An assessment of precision and power using computer simulation

Parameters Selected parameter values Parameter affects precision Parameter affects power
Parameters with variable values    
Number of general practices conducting CRR 1, 10, 20, 50, 100, 150, 200, 250, 300
Number of unique patient records reviewed by each practice at a given point in time 20, 25, 50, 100, 150, 200
The real harm rate in the sampled patient population, expressed as incidents per 100 patients per year 2, 5, 10, 20
The actual reduction in the real harm rate over 12 months 20%, 50%  
Inter-patient variation in harm susceptibility, expressed as a median rate ratio (MRR) 1.2, 2
Parameters with fixed values    
Inter-practice variation in harm susceptibility, expressed as a MRR 1.2
Period of time reviewer reviewed in each record (calendar months) 3
Period of time over which changes in harm rates are examined (months) 12  
Number of reviews during the simulated 12-month period 2  
Reviews at different time points are conducted on the same or different samples of patient records Same  
  1. The different parameters and parameter values can potentially be combined in 864 uniquely different CRR scenarios.