Logopedics Phoniatrics Vocology, 2015; 40: 91–92
LPV FORUM
An estimation of the population incidence of adult unilateral vocal fold mobility impairment in England
S. A. REZA NOURAEI1,2, STEVE E. MIDDLETON3, COLIN R. BUTLER1 & GURI S. SANDHU1 1The
National Centre for Airway Reconstruction, Department of Otolaryngology, Charing Cross Hospital, London W6 8RF, UK, 2Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford CM1 1SQ, UK, and 3Dr Foster Intelligence Ltd, London, UK
Abstract We estimate the population incidence of adult unilateral vocal fold mobility impairment at 5.13 per 100,000 per year. Key words: Population incidence, unilateral vocal fold immobility, vocal fold palsy, vocal palsy
Unilateral vocal fold mobility impairment (UVFMI) is commonly evaluated and treated by otolaryngologists and speech and language pathologists. Much of the literature on this condition has been generated through single-institution case series, and population-level incidence of this condition remains inadequately defined (1). This knowledge is crucial for epidemiological studies and resource planning, particularly in the context of subspecialization of laryngological services. To address this, we performed a calculation to estimate the incidence of UVFMI. We performed an electronic search of our departmental clinic and discharge letters database and identified all communications containing the words ‘vocal’, ‘laryn∗’, ‘voice’, ‘pals∗’, ‘recurrent’, ‘paralysis’, ‘paresis’, ‘bowing’, ‘movement’, or ‘mobility’. Two otolaryngologists then examined the records of all patients identified through this search and manually identified 108 patients with an endoscopically confirmed diagnosis of UVFMI over a 3-year period. In order to avoid referral bias resulting from tertiary and national referrals, only patients referred from three primary care trusts (PCTs) for which our institution is the primary provider were included. English primary care is organized within primary care trusts which hold the health care budget of a population of 150,000–300,000 patients. Although
patients can be referred to any hospital provider, in practice the majority of patients from a ‘host’ primary care trust are referred to a local hospital. We identified 29 males and 27 females who were referred to our institution from amidst our local catchment area. Mean age at diagnosis was 62 ⫾ 15 (range 26–87). There were 43 left-sided and 13 rightsided vocal fold palsies, and in 39% of patients UVFMI was classed as idiopathic (Figure 1). Using Hospital Episode Statistics (HES; www. hscic.gov.uk), which is a record of all inpatient and outpatient encounters of all patients admitted to or seen in ambulatory or outpatients settings in England, we calculated the proportion of otolaryngology referrals generated from within each of the three PCTs to our institution in order to ‘adjust’ the numerator of UVFMI incidence. For example, 71.9% of otolaryngology referrals from Hammersmith and Fulham PCT were to our institution. The mean annual number of UVFMI referrals from this PCT was 7.3 patients, which adjusted to 10.2 once ‘market share’ was taken account of. We then obtained the average number of patients over 16 years of age within each PCT over the same period and used this denominator to calculate the incidence of UVFP at 5.13 adult patients per 100,000 population per year. This extrapolates to 2,087 new diagnoses of
Correspondence: Mr Reza Nouraei MA BChir PhD MRCS, Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford, CM1 1SQ, UK. E-mail: [email protected] (Received 24 December 2013 ; accepted 1 March 2014 ) ISSN 1401-5439 print/ISSN 1651-2022 online © 2014 Informa UK, Ltd. DOI: 10.3109/14015439.2014.902497
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Figure 1. Causes of unilateral vocal fold mobility impairment within the present study.
UVFMI in adults in England per year. Four patients (7.1%) from our primary catchment area underwent implant-based medialization thyroplasty, and 12 patients (23.2%) had injection thyroplasty procedures. Twenty-five (45%) patients were treated by speech and language therapists. We found that the mean number of implant-based medialization thyroplasties over the past years (www.hscic.gov.uk; OPCS code E33.5; n ⫽ 153) (2) triangulates to within 97% accurately with the number of such operations extrapolated from our calculation (n ⫽ 0.0714 ⫻ 2087 ⫽ 149). We accept that this methodology has limitations, mainly that its denominator is based on 1.2% of the English population (n ⫽ 491,000) and, in adjusting for the numerator, we have assumed that the proportion of patients with UVFMI who are referred from a PCT to our institution is the same as the proportion of patients who are referred from a PCT to the otolaryngology service at our institution overall. Despite these limitations, however, this calculation provides a useful estimate, to our knowledge, for the first time, of the population-level incidence of UVFMI, and the extrapolated number
of medialization thyroplasties it produces does seem to correspond with the actual number of cases performed nationally. Larger-scale research is needed to improve the precision of this calculation, but in our view it does provide a good starting-point for further epidemiological studies and laryngological service planning.
Acknowledgements The authors wish to acknowledge and thank Dr Ifeoma Ikwueke for her assistance in data collection. Declaration of interest: The authors report no conflicts of interest.
References 1. Sulica L, Blitzer A. Vocal fold paralysis. New York: Springer; 2006. 2. NHS connecting for health. OPCS classification of interventions and procedures. 4th ed. Norwich: The Stationary Office; 2011.
Copyright of Logopedics Phoniatrics Vocology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
LPV FORUM
An estimation of the population incidence of adult unilateral vocal fold mobility impairment in England
S. A. REZA NOURAEI1,2, STEVE E. MIDDLETON3, COLIN R. BUTLER1 & GURI S. SANDHU1 1The
National Centre for Airway Reconstruction, Department of Otolaryngology, Charing Cross Hospital, London W6 8RF, UK, 2Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford CM1 1SQ, UK, and 3Dr Foster Intelligence Ltd, London, UK
Abstract We estimate the population incidence of adult unilateral vocal fold mobility impairment at 5.13 per 100,000 per year. Key words: Population incidence, unilateral vocal fold immobility, vocal fold palsy, vocal palsy
Unilateral vocal fold mobility impairment (UVFMI) is commonly evaluated and treated by otolaryngologists and speech and language pathologists. Much of the literature on this condition has been generated through single-institution case series, and population-level incidence of this condition remains inadequately defined (1). This knowledge is crucial for epidemiological studies and resource planning, particularly in the context of subspecialization of laryngological services. To address this, we performed a calculation to estimate the incidence of UVFMI. We performed an electronic search of our departmental clinic and discharge letters database and identified all communications containing the words ‘vocal’, ‘laryn∗’, ‘voice’, ‘pals∗’, ‘recurrent’, ‘paralysis’, ‘paresis’, ‘bowing’, ‘movement’, or ‘mobility’. Two otolaryngologists then examined the records of all patients identified through this search and manually identified 108 patients with an endoscopically confirmed diagnosis of UVFMI over a 3-year period. In order to avoid referral bias resulting from tertiary and national referrals, only patients referred from three primary care trusts (PCTs) for which our institution is the primary provider were included. English primary care is organized within primary care trusts which hold the health care budget of a population of 150,000–300,000 patients. Although
patients can be referred to any hospital provider, in practice the majority of patients from a ‘host’ primary care trust are referred to a local hospital. We identified 29 males and 27 females who were referred to our institution from amidst our local catchment area. Mean age at diagnosis was 62 ⫾ 15 (range 26–87). There were 43 left-sided and 13 rightsided vocal fold palsies, and in 39% of patients UVFMI was classed as idiopathic (Figure 1). Using Hospital Episode Statistics (HES; www. hscic.gov.uk), which is a record of all inpatient and outpatient encounters of all patients admitted to or seen in ambulatory or outpatients settings in England, we calculated the proportion of otolaryngology referrals generated from within each of the three PCTs to our institution in order to ‘adjust’ the numerator of UVFMI incidence. For example, 71.9% of otolaryngology referrals from Hammersmith and Fulham PCT were to our institution. The mean annual number of UVFMI referrals from this PCT was 7.3 patients, which adjusted to 10.2 once ‘market share’ was taken account of. We then obtained the average number of patients over 16 years of age within each PCT over the same period and used this denominator to calculate the incidence of UVFP at 5.13 adult patients per 100,000 population per year. This extrapolates to 2,087 new diagnoses of
Correspondence: Mr Reza Nouraei MA BChir PhD MRCS, Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford, CM1 1SQ, UK. E-mail: [email protected] (Received 24 December 2013 ; accepted 1 March 2014 ) ISSN 1401-5439 print/ISSN 1651-2022 online © 2014 Informa UK, Ltd. DOI: 10.3109/14015439.2014.902497
92
S. A. R. Nouraei et al.
Figure 1. Causes of unilateral vocal fold mobility impairment within the present study.
UVFMI in adults in England per year. Four patients (7.1%) from our primary catchment area underwent implant-based medialization thyroplasty, and 12 patients (23.2%) had injection thyroplasty procedures. Twenty-five (45%) patients were treated by speech and language therapists. We found that the mean number of implant-based medialization thyroplasties over the past years (www.hscic.gov.uk; OPCS code E33.5; n ⫽ 153) (2) triangulates to within 97% accurately with the number of such operations extrapolated from our calculation (n ⫽ 0.0714 ⫻ 2087 ⫽ 149). We accept that this methodology has limitations, mainly that its denominator is based on 1.2% of the English population (n ⫽ 491,000) and, in adjusting for the numerator, we have assumed that the proportion of patients with UVFMI who are referred from a PCT to our institution is the same as the proportion of patients who are referred from a PCT to the otolaryngology service at our institution overall. Despite these limitations, however, this calculation provides a useful estimate, to our knowledge, for the first time, of the population-level incidence of UVFMI, and the extrapolated number
of medialization thyroplasties it produces does seem to correspond with the actual number of cases performed nationally. Larger-scale research is needed to improve the precision of this calculation, but in our view it does provide a good starting-point for further epidemiological studies and laryngological service planning.
Acknowledgements The authors wish to acknowledge and thank Dr Ifeoma Ikwueke for her assistance in data collection. Declaration of interest: The authors report no conflicts of interest.
References 1. Sulica L, Blitzer A. Vocal fold paralysis. New York: Springer; 2006. 2. NHS connecting for health. OPCS classification of interventions and procedures. 4th ed. Norwich: The Stationary Office; 2011.
Copyright of Logopedics Phoniatrics Vocology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
