While there is a body of literature from which these guidelines were drawn, significant gaps in our knowledge about hoarseness and its management remain. The guideline committee identified several areas where further research would improve the ability of clinicians to manage hoarse patients optimally.
Hoarseness is known to be common, but the prevalence of hoarseness in certain populations such as children is not well known. Additionally, the prevalence of specific etiologies of hoarseness is not known. Descriptive statistics would help to shape thinking on distribution of resources, levels of care, and cost mandates.
Although a strong intuitive sense of the natural history of many voice disorders exists among practitioners, data are lacking. This dearth of information makes judgments related to the value of observation vs intervention challenging. Some of the entities that might benefit from study include viral laryngitis, fungal laryngitis, inhaler-related laryngitis, voice abuse, reflux, and benign lesions (ie, nodules, polyps, cysts, etc). A better understanding of the natural history of these disorders could be obtained through prospective observational studies and will have clear implications for the necessity and timing of behavioral, medical, and surgical interventions.
Prospective studies on the value of steroids and antibiotics for infectious laryngitis are also lacking. Given the known potential harms from these medications, prospective studies examining the benefits relative to placebo are warranted.
Reflux laryngitis is a very common diagnosis with much controversy surrounding it. While there are a number of studies looking at the use of anti-reflux therapy for chronic laryngitis, the vast majority have severe limitations. Well-conducted and controlled studies of anti-reflux therapy for patients with hoarseness and for patients with signs of laryngeal inflammation would help to establish the value of these medications. Further clarification of which hoarse patients may benefit from reflux treatment would help to optimize outcomes and minimize costs and potential side effects. Future studies may benefit from strict inclusion criteria and specific investigation of the outcome of hoarseness (dysphonia) control.
Although ancillary testing such as radiographic imaging is often performed to assist in diagnosing the underlying cause of hoarseness, the role of these tests has not been clearly defined. Their usefulness as screening tools is unclear and the cost effectiveness of their use has not been established.
Despite data that strongly demonstrate better survival and local control rates in early-stage laryngeal cancers, the improvement of laryngeal cancer outcomes through early screening has not been shown. Study of the effect of early screening and diagnosis is warranted.
Voice therapy has been shown to provide short-term benefit for hoarse patients, but long-term efficacy has not been shown. Also, the relative harm of voice therapy has not been studied (eg, lost work time, anxiety), making the risk/benefit ratio difficult to evaluate.
As office-based procedures are developed to manage causes of hoarseness previously treated in the operating room, comparative studies on the safety and efficacy of office-based procedures relative to those performed under general anesthesia are needed (eg, injection vs open thyroplasty).