Appendix F. Algorithms

Figure 1. Final CABG Algorithm

Figure 1. Final CABG algorithm.  Graphic illustrating classification tree branching for the final CABG algorithm as described in the final report narrative.

Return to Contents

Figure 2. Correlation and Cross-validation error for CABG Algorithm

Figure 2. Correlation and Cross-validation error for CABG Algorithm. Correlation and cross-validation error graphs for CABG, depicting R-square and X-relative error values (y-axis) by number of splits (x-axis).

Return to Contents

Figure 3. Final Algorithm for Herniorrhaphy

Figure 3. Final Algorithm for Herniorrhaphy. Graphic illustrating classification tree branching for the final herniorrhaphy algorithm as described in the final narrative.

Return to Contents

Figure 4. Correlation and Cross Validation Error for Herniorrhaphy

Figure 4. Correlation and Cross Validation Error for Herniorrhaphy. Correlation and cross-validation error graphs for herniorrhaphy, depicting R-square and X-relative error values (y-axis) by number of splits (x-axis).

Return to Contents

Figure 5. Unpruned Algorithm for TKA

Figure 5. Unpruned Algorithm for TKA. Graphic illustrating classification tree branching for the unpruned TKA algorithm as descibed in the final report narrative.

Return to Contents

Figure 6. Correlation and Cross Validation Error for TKA

Figure 6. Correlation and Cross Validation Error for TKA. Correlation and cross-validation error graphs for TKA, depicting R-square and X-relative error values (y-axis) by number of splits (x-axis).

Return to Contents

Figure 7. Final Algorithm for TKA

Figure 7. Final Algorithm for TKA. Graphic illustrating classification tree branching for the final TKA algorithm as described in the final report narrative.

Return to Contents

Figure 8. Final Algorithm for THA

Figure 8. Final Algorithm for THA. Graphic illustrating classification tree branching for the final THA algorithm as described in the final report narrative.

Return to Contents

Figure 9. Correlation and Cross Validation Error for THA

Figure 9. Correlation and Cross Validation Error for THA. Correlation and cross-validation error graphs for THA, depicting R-square and X-relative error values (y-axis) by number of splits (x-axis).

Return to Contents

Algorithms That Include sSSI

Rules using similar protocols as that above that included superficial SSI for training did not perform as well.

Table 1. Preliminary Performance on Training Set (includes sSSI)

 CABGHIPKNEEHERNIA
Total45251969274673867
Algorithm Positive74722381980311
True Positive11622010378
False Negative2819617
Algorithm Sensitivity80.692.194.482.1
% Excluded83.588.673.591.2
NNR Algorithm6.410.219.24
NNR sans Algorithm3989.572.549.6

CABG - Coronary Artery Bypass Grafting, HERNIA - herniorraphy, KNEE - Total Knee Arthroplasty, HIP - Total Hip Arthroplasty, NNR - number needed to read

Return to Contents

Figure 10. Algorithm for CABG (includes sSSI)

Figure 10. Algorithm for CABG (includes sSSI). Graphic illustrating classification tree branching for the CABG algorithm including sSSI, as described in the final report narrative.

Return to Contents

Figure 11. Algorithm for Herniorrhaphy (Includes sSSI)

Figure 11. Algorithm for Herniorrhaphy (includes sSSI). Graphic illustrating classification tree branching for the herniorrhaphy algorithm including sSSI, as described in the final report narrative.

Return to Contents

Figure 12. Algorithm for TKA (Includes sSSI)

Figure 11. Algorithm for TKA (includes sSSI). Graphic illustrating classification tree branching for the TKA algorithm including sSSI, as described in the final report narrative.

Return to Contents

Figure 13. Algorithm for THA (Includes sSSI)

Figure 13. Algorithm for THA (includes sSSI). Graphic illustrating classification tree branching for the THA algorithm including sSSI, as described in the final report narrative.

Page last reviewed December 2012
Internet Citation: Appendix F. Algorithms. December 2012. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/final-reports/ssi/ssiapf.html