Background
Methods
Study Population
BeLPT test
Pulmonary Physiologic Assessment
Chest Radiographs
Health and Exposure Survey
Classification of Baseline Status
Criteria for Clinical Abnormality at Follow-up
Statistical Analysis
Results
Recruitment and Baseline Characteristics
BeS COPD in (n = 50) | CBD COPD in (n = 22) | P value | BeS COPD out (n = 40) | CBD COPD out (n = 20) | P value | |
---|---|---|---|---|---|---|
Age in years (s.d.) | 44.2 (11.1) | 47.8 (10.5) | 0.20 | 42.6 (11.2) | 46.7 (10.2) | 0.17 |
Sex (%male) | 78 | 77 | 0.95 | 73 | 80 | 0.53 |
Race (% white) | 94 | 100 | 0.71 | 93 | 100 | 0.66 |
Smoking Status | ||||||
Non-smoker% | 42 | 36 | 50 | 40 | ||
Ex smoker % | 20 | 36 | 0.32 | 18 | 40 | 0.16 |
Current smoker % | 38 | 27 | 33 | 20 | ||
Mean length from hire date to baseline evaluation in years (s.d) | 12.4 (11.1) | 13.7 (7.0) | 0.60 | 11.6 (10.1) | 14.3 (7.0) | 0.28 |
Period of beryllium exposure in years (s.d) | 15.6 (11.8) | 18.0 (8.4) | 0.41 | 15.1 (11.7) | 18.7 (8.5) | 0.22 |
Time from baseline to follow-up evaluation(s.d) | 7.1 (3.0) | 8.1 (3.4) | 0.20 | 7.0 (3.0) | 8.5 (3.4) | 0.09 |
History of hay fever, asthma or eczema (% positive) | 48 | 50 | 0.96 | 50 | 45 | 0.72 |
Pulmonary Function Tests
| ||||||
FEV1 mean % predicted (s.d.) | 89.3 (14.5) | 86.2 (16.7) | 0.43 | 92.6 (12.7) | 89.1 (14.3) | 0.33 |
FVC mean % predicted (s.d.) | 96.1 (14.8) | 88.8 (11.7) | 0.04 | 97.9 (14.3) | 89.6 (11.5) | 0.03 |
FEV1/FVC mean % predicted (s.d) | 92.8 (10.3) | 95.0 (12.0) | 0.44 | 95.6 (8.1) | 97.0 (8.1) | 0.52 |
DLCO mean % predicted (s.d.) | 101.3 (16.1) | 99.9 (23) | 0.77 | 103.6 (14.2) | 104.0 (20.1) | 0.94 |
TLC mean %(predicted) (s.d.) | 98.6 (14.6) | 94.5 (14.5) | 0.35 | 98.6 (14.3) | 91.5 (12.0) | 0.10 |
Clinical evidence of COPD N (%) | 10 (20) | 2 (9.1) | 0.32 |
Clinical Outcome at Follow-Up
Pulmonary Function Tests | BeS COPD In | BeS COPD out | BeS COPD | CBD COPD In | CBD COPD out | CBD COPD | |
---|---|---|---|---|---|---|---|
N | 50 | 40 | 10 | 22 | 20 | 2 | |
FEV1 % | Before | 89.3 | 92.6 | 76.2 | 86.2 | 89.1 | 57.9 |
After | 88.2 | 91.1 | 77.0 | 82.7 | 86.2 | 48.4 | |
Difference
|
1.1
|
1.6
|
-0.8
|
3.5
|
2.9
|
9.5
| |
FVC % | Before | 96.1 | 97.9 | 89.1 | 88.8 | 89.6 | 80.9 |
After | 94.4 | 94.6 | 93.5 | 87.0 | 88.9 | 67.5 | |
Difference
|
1.8
|
3.3
|
-4.4
|
1.9
|
0.7
|
13.5
| |
FEV1/FVC % | Before | 92.8 | 95.6 | 81.8 | 95.0 | 97.0 | 74.5 |
After | 92.9 | 95.6 | 82.0 | 95.0 | 98.0 | 64.9 | |
Difference
|
-0.0
|
-0.0
|
-0.2
|
-0.0
|
-1.0
|
9.6
| |
DLCO mean %* | Before | 101.3 | 103.6 | 92.2 | 99.9 | 104.0 | 59.4 |
After | 85.7 | 87.8 | 75.5 | 79.6 | 83.4 | 41.8 | |
Difference
|
16.0
|
15.8
|
16.7
|
20.3
|
20.6
|
17.6
| |
TLC mean %* | Before | 98.6 | 98.6 | 98.7 | 94.5 | 91.5 | 125.1 |
After | 94.5 | 93.5 | 98.2 | 86.4 | 85.6 | 94.3 | |
Difference
|
4.2
|
5.1
|
0.5
|
8.1
|
5.9
|
30.8
|
Parameter | Pt.1 | Pt.2 | Pt. 3 | Pt.4 | Pt 5 | Pt 6 | Pt.7 | Pt.8 |
---|---|---|---|---|---|---|---|---|
Baseline diagnosis
| CBD | CBD | CBD | CBD | CBD | CBD | CBD | BeS |
Baseline to current evaluation, in yrs. | 12 | 5 | 12 | 4 | 1 | 9 | 11 | 7 |
Yrs. since first worked at site to initial evaluation | 4 | 10 | 23 | 1 | 26 | 22 | 8 | 18 |
Yrs. of beryllium exposure | 15 | 12 | 29 | 2 | 27 | 36 | 10 | 25 |
Yrs. since last worked at site | 6 | 3 | 6 | 3 | 0 | 9 | 10 | 0 |
Smoking Status | Never smoker | Never smoker | Ex smoker | Ex smoker | Ex smoker | Ex smoker | Ex smoker | Current smoker |
No. of pack years | 0 | 0 | 9 | 20 | 11 | 71 | 8 | 21.5 |
Steroid Use | No | Yes (Inhalational) | No | Yes (Inhalational) | No | Yes (Inhalational) | Yes (oral) | No |
BeLPT result (Lab 1/Lab 2) | +/+ | +/- | +/- | +/+ | +/+ | -/- | +/- | +/+ |
Pulmonary Function tests (% predicted)
| ||||||||
FEV1
| ||||||||
Initial | 73 | 87 | 81 | 85 | 65 | 95 | 72 | 87 |
Final | 62 | 93 | 79 | 89 | 63 | 85 | 70 | 71 |
FVC | ||||||||
Initial | 80 | 78 | 82 | 97 | 71 | 121 | 83 | 89 |
Final | 62 | 87 | 82 | 96 | 69 | 89 | 79 | 68 |
FEV1/FVC | ||||||||
Initial | 92 | 111 | 100 | 88 | 92 | 78 | 87 | 97 |
Final | 99 | 107 | 98 | 92 | 89 | 94 | 88 | 106 |
TLC | ||||||||
Initial | 88 | 78 | 97 | 107 | 95 | 96 | 95 | 88 |
Final | 80 | 58 | 88 | 91 | 87 | 89 | N/A | 79 |
DLCO | ||||||||
Initial | 108 | 95 | 124 | 98 | N/A | 97 | 131 | 116 |
Final | 49 | 69 | 56 | 64 | 53 | 62 | N/A | 82 |
X-ray Changes or CBD
| Bilateral hilar adenopathy and diffuse small opacities | None | None | None | None | Borderline enlargement of lymph nodes | None | None |
Basis for Clinical CBD
| X-ray, Low DLCO, Low FVC | Low TLC, Low DLCO | Low DLCO | Low DLCO | Low FVC, Low DLCO | X-ray, Low DLCO | On oral steroids for presumed clinical CBD | Low FVC, Low TLC |
Questionnaire variables | BeS COPD in (n = 50) | CBD COPD in (n = 22) | P value | BeS COPD out (n = 40) | CBD COPD out (n = 20) | P value |
---|---|---|---|---|---|---|
History of hay fever, asthma or eczyma (% positive) | 48 | 50 | 0.96 | 50 | 45 | 0.72 |
Steroid use (Inhaled or Oral) % | 4 | 32 | 0.001 | 5 | 25 | 0.023 |
Smoking Status | ||||||
Nonsmoker % | 42 | 36 | 48 | 40 | ||
Ex smoker % | 42 | 55 | 0.56 | 38 | 55 | 0.32 |
Current smoker % | 16 | 9 | 15 | 5 | ||
% still working at beryllium-using facility | 36 | 23 | 0.27 | 40 | 20 | 0.12 |
Current BeLPT test results %* | ||||||
(+/+) | 17 | 43 | 0.025 | 21 | 42 | 0.03 |
(+/-) | 26 | 33 | 21 | 37 | ||
(-/-) | 57 | 24 | 58 | 21 | ||
Clinical CBD N (%) | 1(2.0%) | 7(31.8%) | 0.001 | 1(2.5) | 7(35.0) | 0 |
Pulmonary Function Tests (% predicted)
| ||||||
FEV1 (s.d) | 88.2(17.4) | 82.7(21.3) | 0.25 | 91.1(13.0) | 86.2(16.7) | 0.22 |
FVC (s.d.) | 94.4 (18.5) | 87.0(18.4) | 0.12 | 94.6(14.0) | 88.9 (15.7) | 0.14 |
FEV1/FVC (s.d) | 92.9 (10.2) | 95.0 (14.1) | 0.47 | 95.6(8.4) | 98.0(9.6) | 0.32 |
DLCO (s.d.) | 85.4(20.8) | 79.6(20.8) | 0.30 | 87.8(15.9) | 83.4(17.4) | 0.36 |
TLC (s.d.) | 94.5(19.1) | 86.4(14.4) | 0.05 | 93.5(14.6) | 85.6(14.7) | 0.07 |
Predictors of Clinical Disease at Follow-up
Baseline Characteristics | WITHOUT clinical CBD at follow-up n = 15 | WITH clinical CBD at follow-up n = 7* | P value |
---|---|---|---|
Age in years (s.d.) | 45.6 (9.27) | 52.6 (12.0) | 0.15 |
Race (% white) | 93 | 100 | 0.48 |
Sex (%male) | 73 | 86 | 0.52 |
History of hay fever, asthma or eczema % | 47 | 57 | 0.65 |
Mean length from hire date to baseline evaluation, in years (s.d) | 13.7 (5.9) | 13.9 (9.4) | 0.95 |
Period of beryllium exposure, in years (s.d) | 18.6 (8.1) | 16.6 (9.7) | 0.61 |
Time from baseline to follow-up evaluation(s.d) | 8.3 (2.9) | 7.7 (4.4) | 0.70 |
Baseline PFTs (% predicted (s.d.))
| |||
FEV1
| 87.5 (16.3) | 83.4 (18.3) | 0.60 |
FVC | 91.2 (12.2) | 83.7 (9.3) | 0.17 |
FEV1/FVC | 95.9 (13.1) | 92.9 (9.9) | 0.60 |
DLCO | 98.1 (23.9) | 104.3 (22.0) | 0.59 |
TLC | 95.8 (17.2) | 92.4 (9.0) | 0.64 |
Follow-up Characteristics
| |||
Smoking Status
| |||
Nonsmoker % | 40 | 29 | |
Ex smoker % | 47 | 71 | 0.44 |
Current smoker % | 13 | 0 | |
% still working at beryllium facility | 27 | 14 | 0.52 |
BeLPT results *
| |||
(+/+) | 40 | 50 | |
(+/-) | 33 | 33 | 0.89 |
(-/-) | 27 | 17 | |
* result for 1 person was missing |
BeLPT Results at Follow-Up
Lab 1 | ||
---|---|---|
Lab 2 | + ve | -ve |
+ ve
| 15 | 12 |
- ve
| 7 | 29 |
K = 0.43, Agreement = 68.06%, P = 0.0008
|