4. DISCUSSION
Although balance impairment in patients with COPD seems to be less important than the other life-threatening symptoms of this disease, the fall and fractures resulting from the balance impairment may lead to a decrease in the quality of life and an increase in morbidity and mortality. Recent studies have shown that balance impairment and falls are frequent in patients with COPD.1,20 Numerous tests ranging from simple clinical tests to more complex tests conducted using diverse devices in the laboratory environment have been utilized to evaluate the balance issues in patients. The decision regarding which test should be used has changed with time, conditions, and personal experiences.21-23 Studies on balance have generally been performed among the elderly, post-operative patients, post-stroke term, and rheumatic disease patients. However, the number of studies investigating balance issues in patients with COPD is low, and even these studies have investigated a small cohort of patients and utilized only a small portion of balance assessment tests. In pulmonary diseases outpatient clinic, it would be more appropriate for the physicians to select easy-to-perform balance assessment tests to enable focusing on the underlying primary disease for the treatment of patients with COPD who are considered to have balance impairment should be evaluated with the shorter tests at first presentation, and these patients should be directed and evaluated in pulmonary rehabilitation. Hence, patients should be evaluated with more complicated tests to reveal the problem in balance mechanism in order to plan and implement a rehabilitation program accordingly.
BBS is the gold standard in balance assessment and also one of the most frequently applied tests for assessing balance in patients with COPD. Recent studies have shown that patients with COPD have significantly lower BBS scores than the normal population.1,5 In our study, we found that 32 (45.1%) of the patients with COPD had balance impairment as per the BBS test. However, since it takes approximately 15 min to perform the BBS test, it is difficult to perform it daily in the complex environment of an outpatient clinic.6
The past studies assert that SLS test is one of the most frequently employed tests for the assessment of balance impairment in patients with COPD, with more balance impairment detected by SLS in patients with COPD relative to that in control subjects.24-26 In our study, SLS test could detect balance impairment in 57 (80.3%) of the patients with COPD. However, when compared to the BBS test, SLS test could detect balance impairment in more number of patients, indicating that SLS is less selective than BBS.
In our study, we detected balance impairment in 66 (92.9%) of the patients with COPD by using the 5STS test. The comparative rate was 50% in the control group. This difference may be attributed to the fatigue of weakened quadriceps muscles in patients with COPD after 5 times of “sitting down and standing up” sequence that extends the times required to finish the test. Since this test has low selectivity with respect to assessing balance impairment in patients with COPD, we suggest that other tests should be performed before STS to eliminate non-essential steps.
We detected balance impairment in 49 (69%) of our patients by using the FSST test. The reason for the greater frequency of detection relative to that by BBS can be the difficulty in comprehending the FSST test. However, the results of FSST are more consistent with BBS in terms of detecting balance impairment when compared to SLS and 5STS. FSST had the second highest correlation with BBS. In addition, while BBS requires 15 min for completion, FSST can be completed in 5 min, which favors the preference for the latter.
In our study, balance impairment was detected in 38 (53.5%) of the patients with TUG test. Among all the tests, TUG gave the closest results with BBS in terms of detecting balance impairment. Morover TUG had the highest correlation with BBS. This test evaluates patients in 3 stages. The test first evaluates the quadriceps muscles when the patient stands up from the chair and sits; this muscle is the most-affected peripheral muscle group in patients with COPD. In the next 2 stages, the balance impairment observed during the daily life activities is evaluated by walking the patient for 3-m (10 ft) and back. Thus, the static and dynamic balances are evaluated by this test. Hence, we believe that this test can produce more objective results in patients with COPD in comparison with other easy-to-perform tests.
SLS and 5STS can evaluate static balance, while TUG and FSST can evaluate both static and dynamic balances. We believe that it would be more accurate to evaluate dynamic balance together with static balance when evaluating the balance issue in patients with COPD, since evaluation of only the static balance will bypass maneuvers that maintain balance during a regular gait. In our study, the closest results to BBS were obtained with TUG and FSST.
In our study, balance impairment and fall history in Group C and D patients with COPD were more frequent than those in Group A and B. COPD exacerbations negatively affect the muscle functions and physical activity levels. As a result, the incidence of fall increased.27 Since Groups C and D had higher frequency of exacerbation, these groups showed more balance impairment and an increased incidence of falls in both the groups.
The risk of balance impairment and falls in patients with COPD are not considered very important by healthcare professionals and patients. However, in our study, we observed that balance impairment and frequency of falls increased in patients with COPD and that the balance test scores could be correlated with functional parameters such as patient’s pulmonary function test parameters, CAT, mMRC, and BODE scores. In this case, we speculate that evaluating patients with COPD with balance tests is a useful approach toward determining balance impairment and risk of falls and for predicting the functional status.
The main limitation of our study was that we did not use the BES and Activities Specific Balance Confidence Scale with BBS in the comparison assessment with SLS, 5STS, FSST, and TUG tests. The former tests are more detailed for the evaluation of balance. However, since all of these 3 tests are relatively more time consuming to apply simultaneously, BBS, which is the most frequently used test, was preferred in this study.