During the study period, 52 patients fulfilled the conditions of the study and they were divided into two groups A and B, having 26 patients each. Males were predominant in both the groups [88.46% (A) and 76.92% (B)] and the difference was statistically insignificant (Chi-square, Fischer exact two tailed P = 0.46). Most of the patients in both the groups [53.84% (A) and 61.53% (B)] belonged to the age group of 15 to 35 years. Mean age was 39.03 ± 16.62 years (A) and 33.69 ± 12.05 years (B), respectively, the difference being statistically insignificant (unpaired student's t = 1.33, P = 0.19). Thus, demographically, both the groups were comparable to each other at baseline.
On chest radiography, 30.77% patients of group A and 26.93% patients of group B had massive pleural effusion, while 69.23% and 73.07% patients of A and B groups, respectively, had moderate pleural effusion before thoracentesis. Initially, none of the patients in either group had minimal pleural effusion. At baseline, both the groups were comparable to each other in terms of the extent of pleural effusion (Yates corrected Chi-square test = 0.00, df = 1, P > 0.05). After initiation of treatment, extent of pleural effusion had reduced in both the groups. At one month after ATT and during subsequent follow-up visits, none of the group A patients had either massive or moderate pleural effusion and only 61.54% had minimal pleural effusion. Among group B patients, 15.38% and 84.62% had moderate and minimal pleural effusion, respectively, after one month of treatment and all the patients had minimal pleural effusion as compared to only 26.93% patients of group A at 2 months of treatment. None of the group A patients had any pleural effusion whereas only five patients in group B had minimal pleural effusion after six months of treatment .
Extent of tuberculous pleural effusion on chest radiograph (N = 52)
Regarding spirometry parameters, both the groups were comparable to each other at baseline in terms of mean percentage predicted of FEV1 (51.54 vs. 49.19, unpaired student's t test = 0.69, P = 0.49), FVC (50.50 vs. 49.23, t test = 0.33, P = 0.74) and FEV1/FVC (101.96 vs. 99.96, t = 1.09, P = 0.27). After thoracentesis during the three different follow-up visits, the percentage predicted of FEV1 and FVC increased in both the groups.
Mean FEV1 value of group A patients increased steadily from 51.54 to 87.62. This increase was statistically significant as evident from Wilks’ Lambda = 0.072, F = 99.545, P < 0.0005. In group B patients, FEV1 also increased significantly over time [Wilks’ Lambda = 0.062, F = 116.13, P < 0.0005]. Multivariate partial eta squared suggests a very large effect size in both group A (0.928) and B (0.938) . At the end of 6 months, FEV1 was significantly higher among group A patients, compared to group B (87.62 vs 84.92, t test = 2.38, P = 0.02).
Line diagram showing mean % predicted FEV1 in both the groups at baseline and follow-up visits
There was also significant increase in mean value of FVC in both the groups [A - Wilks’ Lambda = 0.041, F = 179.51, P < 0.0005, multivariate partial eta squared = 0.959 vs B - Wilks’ Lambda = 0.060, F = 119.20, P < 0.0005, multivariate partial eta squared = 0.940] after treatment with a very large effect . At the end of six months, group A patients had significantly higher FVC as compared to group B patients (86.46 vs. 83.31, t test = 3.28, P = 0.00).
Line diagram showing mean % predicted FVC in both the groups at baseline and follow-up visits
However, in both the groups mean score of FEV1/FVC did not change substantially over time as compared to the baseline [In group A: Wilks′ Lambda = 0.850, F = 1.351, P = 0.282, multivariate partial eta squared = 0.150; In group B: Wilks′ Lambda = 0.832, F = 1.551, P = 0.228, multivariate partial eta squared = 0.168] .
Line diagram showing mean % predicted FEV1/FVC in both the groups at baseline and follow-up visits
Before thoracentesis, pleural thickening was absent in both the groups as demonstrated by color Doppler ultrasonography of thorax. Subsequently, at different point of follow-up visits, pleural thickening appeared in both the groups, though the proportion was less in group A as compared to group B and this was statistically significant throughout the three follow-up visits (P < 0.05) .
Residual pleural thickening in tuberculous pleural effusion (N = 52)