Statistical Analyses
Statistical software (STATA), version 14.2 was used for statistical analysis. Linear regression was used to analyze the continuous FEV1 % predicted variable, number of pulmonary exacerbations, and total number of days hospitalized in the surgical versus non-surgical groups, adjusting for correlational data analysis and effective size measurement. Standard errors were inflated to reflect the degree of correlation. Unadjusted and adjusted analysis was calculated.
RESULTS
Forty patients with CF (mean age 37.4 years, 60% male) were reviewed. Non-surgical patients appear to have higher rates of Pseudomonas, whereas surgical patients have higher rates of MRSA airway colonization (Table 1). Pre-operative and post-operative respiratory cultures (sputum, bronchioalveolar lavage, or sinus culture) were obtained for 11 out of 20 surgical patients. All 11 patients had the same bacterial culture pre-operatively and post-operatively. All 3 of the 11 surgical patients with no growth pre-operatively did not have bacterial growth post-operatively (Table 2).
No significant difference was found between the surgical group and matched non-surgical controls in baseline FEV1 (72.5% vs. 72.7%, p=0.98). The 2-year pre-operative number of pulmonary exacerbations did not show any statistically significant difference (3.05 vs. 1.65, p=0.10) between the two groups. No significant difference was found between the surgical group and matched non-surgical controls in pre-operative Lund-Mackay scores (12.25 vs. 11.55, p=0.71). The 2-year pre-operative total number of days hospitalized did not show any statistically significant difference (4.5 vs. 3.41, p=0.60) between the two groups. (Table 3).
Post-operatively, no significant difference between the surgical group and matched non-surgical controls was found in the 1-year post-operative FEV1 (70.5% vs. 72.8%, p=0.84), 2-year post-operative FEV1 (70.4% vs. 72.6% p=0.80) and 2-year post-operative number of pulmonary exacerbations (1.7 vs. 1.45, p=0.87). There was a significant increase in the 2 year post-operative total number of days hospitalized in the surgical group (6.2 vs. 1.6, p=0.03) (Table 4).
In the surgical group alone, although the trend appeared to show a decrease in FEV1 post-operatively, no significant difference was identified in the change in FEV1 (preoperative to post-operative) at 1 -year post-operatively (-2.51%, p=0.32) and 2-years post-operatively (-3.10%, p=0.51). Although the rate of pulmonary exacerbations post-operatively appears to decrease, this value is not significant (-1.28, p=0.11). The total number of days hospitalized 2 years post-operatively did show a trend towards an increase within the surgical group itself, however, this value was not statistically significant (3.74, p=0.14). (Table 5).
DISCUSSION