This prospective study of 159 patients with RCC adds to the growing body of literature highlighting the management difficulties of this disorder. Most patients in this investigation reported seeking care for their cough from at least four physicians, and trialing at least six different medications intended to treat cough before enrolling in BCST. At the time of enrollment in BCST, patients were still symptomatic, with low LCQ scores, indicating their cough negatively impacted quality of life. Following BCST, the total LCQ score increased on average over 4.6 points, indicating a significant and clinically meaningful improvement. Given the majority of participants included in this study reported having been prescribed four or more ineffective medications prior to BCST, these data suggest that BCST is at least as effective as some medical intervention for cough in the sample studied here. Given the average wait time to see a physician in the United States is approximately 24 days[20] and the most commonly prescribed empiric treatments for RCC (i.e., pharmaceutical treatments for rhinitis, GERD, or asthma) require a one-to-six-month trial period to determine effectiveness [21], the health and financial burden of such a protracted time to symptom resolution is significant.
Pharmaceutical treatments directly targeting cough hypersensitivity have been shown to be helpful in a proportion of patients with RCC; however, the data presented here suggests BCST is at least as, or more, effective, and with a much lower risk profile. Ryan et al. (2012) [22] is one of the few neuromodulator efficacy studies to include the LCQ as an outcome measure, allowing for direct cross-study comparison. Their placebo-controlled trial showed a mean change in LCQ of 2.5, which is nearly 2 full points lower than the mean LCQ change of 4.66 in the current study. Furthermore, 31% of the participants in Ryan et al.’s study experienced negative side effects. Our data also shows BCST to be superior to low dose morphine, which has been shown to reduce symptoms in approximately half of patients with RCC [8] with an average change in LCQ of 3.2.
The 2020 Medicare charge[23] for the most commonly prescribed tests for patients with RCC (i.e., chest CT, sinus CT, laryngoscopy, pulmonary function testing, allergy testing, swallow study, pH reflux testing) totals over $1200. With the average initial visit charge being $110, and the patients in this sample seeing on average at least 4 different physicians, $440 is spent on initial physician visits alone, totally over $1500 in tests and physician charges without counting the cost of repeat physician visits or medications (see Table 4). Conversely, the cost of one session of BCST is $81.20. Although we did not collect data on number of BCST sessions, prior studies indicate patients undergoing BCST typically receive no more than four sessions, for a total cost of $417.19. Further, and perhaps most importantly, these patients completed BCST after failing medical therapies, and only after BCST did they experience a meaningful improvement. Nearly 60% reported high satisfaction and symptom resolution with BCST, 29% of whom reported their cough was nearly or completely gone.
Results of the current investigation support past BCST efficacy literature. In 1988, Blager [24] reported on four patients with refractory cough of presumed psychogenic origin. One patient underwent BCST with symptom resolution and cessation of cough suppression medications. In 2006, Vertigan and colleagues [25] published a prospective randomized placebo-controlled trial of four sessions of BCST (n=47) compared to healthy lifestyle education training (n=50). Eighty-eight percent of participants in the intervention group achieved a significant reduction in cough, compared to only 14% in the placebo group. Like participants in the current study, those in the Vertigan investigation underwent multiple diagnostic tests and medication trials prior to initiation of BCST. In 2017, Chamberlain Mitchell and colleagues [26] reported an improvement in LCQ of 3.4 in 34 patients following four sessions of BCST compared to improvement of only 1.53 in 41 control patients. Like the Vertigan study and ours, these patients had failed common empiric treatments prior to enrolling in BCST. Patients in the current study improved an average of 3.2 points more on the LCQ than the intervention group in the Chamberlain Mitchell investigation, adding further evidence to the strong efficacy of BCST. Taken together, the extant literature and the current investigation demonstrate that BCST is efficacious at reducing or eliminating cough, and cost-effective when compared to empiric medical treatments. Further, BCST can be initiated at any time in the diagnostic process without sacrificing accuracy of other diagnostic tests or empiric treatments. For example, patients could be offered BCST concurrently with empiric treatment for GERD, assuming they also have peptic symptoms (see, European Respiratory Guidelines [8]), which requires at least four weeks of medical management before symptom change [27].
The results of this survey highlight the need for several areas of future investigation. Randomized controlled trials would be beneficial for determining the role of first-line medical and behavioral and combined medical/behavioral therapies in improving objective measures of cough and quality-of-life. Based on the present data, we suggest consideration of early intervention with BCST is potentially more cost-effective and efficient for treating RCC than the conventional treatment model. An example of early intervention is offering BCST to a patient who visits their primary care physician because they have been coughing for eight weeks following a resolved upper respiratory tract infection. Current standard of care is to first evaluate for red flags and obtain a chest x-ray, then prescribe empiric trials of proton pump inhibitors, inhalers, and/or nasal sprays, and finally refer to a pulmonologist and/or otolaryngologist if symptoms persist[28]. Future care could involve initiation of BCST at the time of empiric treatment. In some cases, early initiation of BCST might even expedite appropriate evaluation by specialists, as experienced SLPs with training in laryngeal and upper airway disorders may be able to recognize features of RCC that are consistent with more concerning pathologies (i.e., subglottic stenosis, tracheobronchomalacia, vocal fold lesions).