Table 4.

Data about tracheal stenoses after PDT from follow-up investigations with telephone interview and questionnaire

Authors (year)/reference	Design	Number of patients	Tracheotomy method	Number of patients with tracheal stenosis, (%)	Time of follow-up (months)	Type of follow-up
Hill et al. (1996) [18]	prospective	p 353 f 214	PDT (C)	symptomatic stenosis 8 (3.7)	10	telephone interview, clinical examination
Law et al. (1997) [19]	prospective	p 109 f 41	PDT (C)	stenosis > 40% 1 (2.4)	6	telephone interview, spirometry, endoscopy
Rosenbower et al. (1998) [20]	prospective	p 95 f 55	PDT (C)	subglottic stenosis 2 (2.0)	12	endoscopy ENT, telephone interview
Norwood et al. (2000) [17]	prospective	p 422 f 100	PDT (C)	stenosis > 50% 3 (3.0)	26	telephone interview, endoscopy, CT
Escarment et al. (2000) [21]	prospective	p 162 f 81	GWDF (G)	surgery due to stenosis 4 (4.9)	3	clinical visit, endoscopy, telephone interview
Dollner et al. (2002) [22]	retrospective	p 60 f 19	GWDF (G)	stenosis > 25–50% 2 (3.3) stenosis > 50% 1 (1.6)	17	telephone interview, clinical examination, endoscopy
Young et al. (2014) [23]	prospective	p 120 f 50	PDT (B)	stenosis > 46% 5 (4.0)	3	questionnaire, MRI, spirometry

B: PDT acc. to Ciaglia Blue Rhino, p: number of patients who received PDT

C: PDT acc. to Ciaglia, f: number of patients, available for follow-up examination

G: GWDF acc. to Griggs, CT Computerized tomography

MRI Magnetic resonance imaging