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