Subgroup analysis of need for surgical intervention compared with estimated income quartiles.
| Quartile | Surgical | Conservative | Total | % Failure of Medical Management |
| Q1 | 16 | 21 | 37 | 43.20% |
| Q2 | 8 | 30 | 38 | 21.10% |
| Q3 | 11 | 27 | 38 | 28.90% |
| Q4 | 7 | 30 | 37 | 18.90% |
Note: P = 0.08