Significant predictors for primary treatment failure of suspected microbial keratitis
| Characteristics | Primary treatment failure | Risk ratio | 95% CI | p Value | |||||
|---|---|---|---|---|---|---|---|---|---|
| No | % | ||||||||
| “Crude” estimates of risk ratio with no adjustment for confounding factors | |||||||||
| Culture positive ulcers >5 mm2 | 11/26 | 42.3 | 12.8 | 3.9–43.1 | <0.001 | ||||
| Other ulcers | 3/92 | 3.3 | |||||||
| Age 60+ years | 13/42 | 40.0 | 23.5 | 3.2–173.6 | <0.001 | ||||
| Age <60 years | 1/76 | 1.3 | |||||||
| Previous corneal disease | 11/38 | 28.9 | 7.7 | 2.3–26.1 | <0.001 | ||||
| No previous corneal disease | 3/80 | 3.8 | |||||||
| Topical steroid treatment | 6/19 | 31.6 | 3.9 | 1.5–10.0 | 0.01 | ||||
| No steroid | 8/99 | 8.1 | |||||||
| Hypopyon present | 5/15 | 33.3 | 3.8 | 1.5–9.9 | 0.017 | ||||
| No hypopyon | 9/103 | 8.7 | |||||||
| Variables in regression model | Adjusted risk ratio | 95% CI | p Value | ||||||
| Results of multiple regression analysis for risk factors with adjustment for confounding factors | |||||||||
| Culture positive ulcers >5 mm2 v other ulcers | 5.5 | 1.4–20.8 | 0.013 | ||||||
| Age 60+v age <60 years | 11.0 | 1.3–92.1 | 0.027 | ||||||
Further adjustment for confounding effect of other factors one at a time did not materially change the results.