- Email: [email protected]
The Development of a Snoring Symptoms Inventory
Otolaryngology–Head and Neck Surgery (2006) 134, 56-62
ORIGINAL RESEARCH
The Development of a Snoring Symptoms Inventory Susan A. Douglas, FRCS-Ed, FRCS (ORL), Simon Webster, MMathStat, Mohammed Reda El Badawey, MD, FRCS (ORL), Michael Drinnan, PhD, John N. S. Matthews, MA, PhD, G. John Gibson, BSc, MD, FRCP, FRCP-Ed, and Janet A. Wilson, MD, FRCS-Ed, FRCS, Nottingham and Newcastle upon Tyne, United Kingdom OBJECTIVE: To develop a patient-derived snoring questionnaire, the Snoring Symptoms Inventory (SSI), and explore its structure and relationship to the Epworth Sleepiness Scale (ESS); and to assess the sensitivity of the SSI to change. STUDY DESIGN AND SETTING: The SSI was developed from an open-ended questionnaire given to 120 habitual snorers. The 25 symptoms reported compose the SSI. This study examines 261 subsequent snorers assessed between April 1998 and August 2002, who completed both the SSI and the ESS. Fifty-five of them underwent laser uvulopalatoplasty and their preoperative and postoperative SSI results were compared. RESULTS: The total SSI score is the key outcome derived. Principal component analysis identified two further dimensions, one contrasting family/social with work-related problems and another comparing physical problems with embarrassment. The total score correlated weakly with the ESS. Laser uvulopalatoplasty significantly reduced patients’ overall symptom severity and family and socially related problems. CONCLUSION: The SSI is a comprehensive and sensitive measure for assessing snoring, making it a useful clinical outcome tool for snoring treatment. SIGNIFICANCE: The SSI is a new, useful snoring questionnaire. EBM rating: B-2b © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
From The Queen’s Medical Centre, Nottingham (Dr Douglas), The University of Newcastle upon Tyne (Mr Webster and Drs Drinnan, Matthews, Gibson, and Wilson), and ⫹The Freeman Hospital, Newcastle upon Tyne (Dr El Badawey). Presented at The British Association of Otolaryngology–Head and Neck Surgery, May 2002 and at the Annual Meeting of the American
S
noring is a ubiquitous condition and has been found to increase in frequency with age. In a telephone survey in the United Kingdom, 40.3% of the respondents reported snoring, with a prevalence of snoring increasing with age up to 55 years and also higher in men than women.1 Snorers are commonly overweight1 and frustrated by the social consequences of their noisy night-time resonance, but other symptoms are frequently variable. The most commonly used questionnaire in snoring patients is the Epworth Sleepiness Scale (ESS),2 but this focuses only on daytime somnolence and does not address the other consequences of snoring. It has been shown that questionnaires based on information obtained from patients may give a more accurate view of the symptoms than those designed exclusively by clinicians.3 Emphasis on the patients’ point of view enables the otolaryngologist to judge therapy in a manner that more closely reflects the way in which patients assess their own health. Reliable and sensitive self-report measures for snoring are currently lacking, which makes assessment of the outcomes of snoring surgery haphazard: the patient’s and partner’s self report are vital in the evaluation of snoring therapy, yet many otherwise well-designed studies report only a summary outcome such as visual analogue scores of a few items. There is a need for a snoring questionnaire that provides a comprehensive view of the consequent symptoms, and which is responsive to change after intervention. Academy of Otolaryngology–Head and Neck Surgery, Orlando, FL, September 21-24, 2003. Reprint requests: Susan Douglas, The Queens Medical Centre, Derby Road, Nottingham NG7 2UH, UK. E-mail address: [email protected].
0194-5998/$32.00 © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.09.006
Douglas et al
The Development of a Snoring Symptoms . . .
In our previous study4,5 120 habitual snorers were asked to list in an open fashion all the problems they had as a result of snoring. The study compared the symptoms as reported by the patient and the otolaryngologist. Otolaryngologists were more likely to record diurnal somnolence, sleep apnea, and relationship problems as the main symptoms of snorers, whereas habitual snorers more often cited disturbance of others’ sleep, irritability, and physical symptoms such as a dry mouth, breathing difficulty, lethargy, and choking.
AIMS The aims of the present study were: 1) to determine the principal factors measured by the Snoring Symptoms Inventory (SSI) and the relationship, if any, of these factors to the ESS; and 2) to establish the sensitivity to change of the SSI.
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METHODS The symptoms reported by the patients in our previous open-ended questionnaire were collated in the form of a 25-item snoring questionnaire—the Snoring Symptoms Inventory (SSI). The answer to each question had a 5-point severity scale, where 0 ⫽ strongly disagree, 1 ⫽ disagree, 2 ⫽ neither agree nor disagree, 3 ⫽ agree, 4 ⫽ strongly agree (see Appendix). Patients attending a snoring clinic between April 1998 and August 2002 were asked to complete the Snoring Symptoms Inventory and the Epworth Sleepiness Scale. Complete data sets were available for 261 patients, 200 males and 61 females, with an age range of 24 to 69 years (mean age 43.6 years). As larger scores indicated a more severe problem with snoring, the primary outcome of the questionnaire is the total of the 25 scores, ie, a value between 0 and 100, with 0
Table 1 Summaries of the responses to each question on the SSI in 261 habitual snorers Item 1* 2* 3* 4*
5* 6* 7 8*
9* 10 11 12 13 14 15 16 17 18 19 20 21* 22 23 24 25*
My sleep is disturbed My family complains about my snoring I feel tired I am concerned about disturbing my partner’s sleep or the sleep of others in the home I have a dry mouth or throat I am embarrassed when I stay overnight with friends or relatives I have a blocked nose Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home I am concerned that my snoring puts a strain on my personal relationship(s) I worry about falling asleep whilst driving I am embarrassed when I am on holiday or staying in hotels I feel bad tempered and irritable I sometimes fall asleep during the day I have a sore throat My sex life has been affected by my snoring I have problems concentrating on my work My neighbors complain about my snoring I am unable to concentrate during the day I lack self-confidence I have a choking feeling I feel depressed because I cannot do anything about my snoring I get headaches I have problems breathing I feel frightened of going to sleep I am embarrassed by my snoring
Mean score
Median score
Lower quartile
Upper quartile
2.77 3.24 2.79 3.72
3.0 4.0 3.0 4.0
2.0 3.0 2.0 4.0
4.0 4.0 3.5 4.0
2.59 2.84
3.0 3.0
2.0 2.0
3.0 4.0
2.38 2.89
3.0 3.0
1.0 2.0
3.0 4.0
3.25
4.0
3.0
4.0
1.20 2.45
1.0 3.0
0.0 2.0
2.0 3.0
2.44 2.51 1.81 2.32 1.79 1.27 1.71 1.49 1.76 2.56
3.0 3.0 2.0 3.0 2.0 1.0 2.0 1.0 2.0 3.0
2.0 2.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 2.0
3.0 3.0 3.0 3.0 3.0 2.0 3.0 2.0 3.0 3.0
1.98 2.13 1.40 3.10
2.0 2.0 1.0 3.0
1.0 1.0 1.0 3.0
3.0 3.0 2.0 4.0
For every question the minimum and maximum scores reported were 0 and 4. * ⫽ The 10 items with the largest mean scores.
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Otolaryngology–Head and Neck Surgery, Vol 134, No 1, January 2006 Fifty-five of these patients underwent laser uvulopalatoplasty (LAUP) and their preoperative and postoperative SSI data were compared in order to assess the questionnaire’s sensitivity to change.
RESULTS Total Score
Figure 1 Histogram of the total score for the SSI from 261 habitual snorers.
corresponding to no problems with snoring. The distribution of the total score, and its relationship with the age and sex of the patient and with the ESS, were described using standard statistical methods: histograms, scatter plots, t tests, and regression. Although each respondent gives 25 responses, we hypothesized that there are likely to be links between these different responses, such that there are, in fact, fewer separate aspects to the patient’s problems. These links will be reflected by common patterns in his or her response. The principal component analysis uncovers these common patterns by exploring the deeper structure of the correlation matrix of the responses. This also tells us if these links account for a substantial proportion of the total variation of the responses. Each link or component is reported as a linear combination of the scores on the individual questions. This method produces useful information if 1) most of the variation in the scores can be described by a few components and 2) the nature of the linear combinations permits a simple interpretation of the meaning of the score. For more details see “Statistical methods in medical research.”6 The relationships between the components and the total score of the ESS were also explored. Cronbach’s alpha statistic was calculated as a measure of the reliability of the questionnaire.
The means, medians and quartiles for the responses from each question are listed in Table 1. The histogram of the total score is shown Figure 1. The mean, standard deviation, and 95% confidence interval (the interval which contains 95% of the population) are shown in Table 2 for the total score overall and separately for men and women. The difference in means between males and females is 5.13 (P ⫽ 0.005, 95% confidence interval 1.56, 8.69), with the scores slightly higher for females. There is no evidence of a relationship with age (Pearson correlation ⫽ ⫺0.06, P ⫽ 0.34) but clear evidence that the total score increases with increasing ESS.
Principal Components Analysis The principal components analysis identified three components, which explain most variation: ⫺21%, 11%, and 6% respectively of the total variation (Table 3). Questions with large positive coefficients will give positive values on the component, in contrast to questions with large negative values, which will tend to give negative values to the component. Those questions associated with the numerically large coefficients dominate the component; important weightings are taken as coefficients greater than 0.15 for positive items, less than ⫺0.15 for negative items. The first component has coefficients that are all positive and of broadly similar size. This gives a component with properties very similar to the total score used above: the correlation between the score on the first component and the total score is 0.98 (P ⬍ 0.0001). In other words, the first component is effectively a measure of the overall severity of the symptoms recorded in the SSI. The second component gives large positive weighting to items 2, 4, 6, 8, 9, 11, 15, 21, and 25. These are all connected with the effects of snoring on other family
Table 2 Summary values for total scores, Social-Work and Physical-Embarrassment scores in 261 snorers Variable
Mean
SD
Total score Total score n ⫽ 61 females Total score n ⫽ 200 males Social-Work Physical-Embarrassment
58.4 62.3 57.2 17.56 8.42
12.5 13.4 12.0 6.37 4.45
95% Confidence interval 33.8, 36.0, 33.6, 5.09, ⫺0.30,
83.0 88.6 80.8 30.04 17.14
Correlation with ESS 0.39, 0.44, 0.38, ⫺0.18, 0.10,
P P P P P
⬍ ⬍ ⬍ ⫽ ⫽
0.0005 0.0005 0.0005 0.004 0.10
Douglas et al
The Development of a Snoring Symptoms . . .
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Table 3 Coefficients of the first three components from the principal component analysis Component Item
Statement
1
2
3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Sleep disturbed Family complains about snoring Feel tired Partner/others in house has sleep disturbed Dry mouth or throat Embarrassed when staying with friends Blocked nose Sleep separately from partner sometimes Strain on personal relationships Worry about falling asleep driving Embarrassed when on holiday/in hotels Bad-tempered and irritable Fall asleep during day Sore throat Sex life affected by snoring Problems concentrating on work Neighbors complain about snoring Unable to concentrate during day Lack self-confidence Choking feeling Cannot do anything about snoring Headaches Problems with breathing Frightened of going to sleep Embarrassed by snoring Associated eigenvalue
0.21 0.03 0.25 0.09 0.14 0.19 0.10 0.03 0.11 0.14 0.22 0.25 0.17 0.18 0.10 0.24 0.17 0.25 0.20 0.17 0.18 0.20 0.20 0.22 0.20 5.40
⫺0.07 0.17 ⫺0.21 0.33 0.04 0.22 ⫺0.07 0.28 0.29 ⫺0.14 0.20 ⫺0.05 ⫺0.15 ⫺0.02 0.19 ⫺0.19 0.09 ⫺0.19 ⫺0.13 ⫺0.03 0.27 ⫺0.14 ⫺0.13 0.05 0.30 2.67
⫺0.08 0.25 ⫺0.02 ⫺0.04 0.33 ⫺0.32 0.33 0.22 0.08 ⫺0.08 ⫺0.15 0.03 ⫺0.05 0.22 0.08 0.04 ⫺0.10 ⫺0.01 ⫺0.08 0.21 ⫺0.02 ⫺0.10 0.15 ⫺0.01 ⫺0.29 1.42
Note for Component 2, Social-Work, and 3, Physical-Embarrassment: important positive weightings in bold, important negative weightings in italic.
members, embarrassment caused by snoring, and feeling unable to do anything about the problem. Large negative values are given to items 3, 13, 16, and 18, which are all related to tiredness and work-related problems. This component will therefore be large (positive) for patients where social and family difficulties are the dominant problem caused by their snoring and small (negative) for those for whom work-related problems and tiredness dominate. The third component gives large positive weighting to items 2, 5, 7, 8, 14, 20, and 23. Items 2 and 8 relate to the disturbance caused by snoring, while all the other items are physical problems suffered by the patient. Large negative weights are given to items 6, 11, and 25, which are all connected with embarrassment. The presence of items 2 and 8 makes interpretation slightly awkward but essentially this component contrasts physical problems with embarrassment: for patients with large positive values, the physical problems of their snoring dominate their embarrassment, while the opposite is true for patients with large negative values.
Calculating Component Scores and Simplified Scores The exact score of a patient on each of the three components (product of the item score and its weighting coefficient; Table 3, Fig 2) is impractical to compute in a clinic. The total score has been shown adequately to reproduce the information in the first component. The Social-Work (SOCWK) component is mirrored by the sum of scores on items 2, 4, 6, 8, 9, 11, 15, 21, and 25 minus the sum of scores returned on 3, 13, 16, and 18. The Physical-Embarrassment (PHYSEMB) component is likewise derived from the sum of 2, 5, 7, 8, 14, 20, and 23 minus the sum of scores on items 6, 11, and 25. These scores are easily computed alternatives to the second and third components respectively. This is demonstrated by the high correlations: Social-Work has a correlation of 0.963 with the second component and Physical-Embarrassment a correlation of 0.944 with the third component. Summary quantities for these scores, including their correlation with ESS, are given in Table 2.
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Otolaryngology–Head and Neck Surgery, Vol 134, No 1, January 2006 patients undergoing LAUP had more severe symptoms, centered on social and family or work. There is strong evidence that both the total score and SOCWK were lower after LAUP (Table 4), whereas the PHYSEMB domain was not statistically different, suggesting the operation has less impact on physical symptoms.
DISCUSSION
Figure 2 Distribution of the Social-Work component and the Physical-Embarrassment component scores in 261 patients.
Questionnaire Reliability The Cronbach’s alpha for the 25 questions of the SSI was 0.81, which demonstrates good reliability.
Change in SSI After Laser Uvulopalatoplasty Fifty-five of the 261 patients whose data have been described above underwent laser uvulopalatoplasty. The preoperative means of total SSI score, SOCWK score, and PHYSEMB score for this subset of patients (83.4, 24, and 11.3 respectively, Table 4) were all larger than the corresponding means for the group as a whole. Thus the
The development of the Snoring Symptoms Inventory gives insight into the various types of symptoms associated with snoring, and is not confined to the effects of sleep apnea. These symptoms are sleep-related, physical, and psychosocial and relationship difficulties. In the original derivation of the SSI, we found that otolaryngologists were more likely to report diurnal somnolence and relationship problems as the main symptoms of habitual snorers, whereas the patients more often cited disturbance of the sleep of others, and lethargy.5 The 10 items with the highest reported scores in the SSI for our group of patients also demonstrated concern about disturbing the sleep of others or that snoring put a strain on personal relationships and embarrassment about snoring (Table1). These features also influenced each of the first three principal components. This reinforces the different viewpoints held by the physician and the patient and that these fundamental differences may mold the patients’ perspective of their problem and treatment. For example, after treatment a patient may not show a very marked reduction in snoring intensity measured in decibels, but if the reduction is sufficient to allow that individual’s partner to sleep in the same bed, the patient is likely to be satisfied with the result. The SSI enables us to assess the patient from the viewpoint of a wider symptom range and thus to achieve a comprehensive analysis of the patient’s problem. The International Classification of Functioning, Disability and Health describes levels of disability with impairments as significant deviation or loss of body function or structures and activity limitation as difficulties experienced in executing certain activities. It has been demonstrated that patients in a hospital clinic often describe problems associated with impairments in preference to those that demonstrate limitation of activity. The patient may report disturbed sleep (impairment) but not report that he is tired throughout the day and
Table 4 Summary of mean SSI scores pre- and post-LAUP Variable
Preop score
Postop score
Mean change preop–postop
95% confidence interval
P
Total SSI score Social-Work Physical-Embarrassment
83.4 24.0 11.3
65.8 15.8 10.9
17.6 8.3 0.4
13.0, 22.1 5.9, 10.7 ⫺0.8, 1.6
⬍0.0005 ⬍0.0005 0.52
Douglas et al
The Development of a Snoring Symptoms . . .
is therefore unable to get a job (activity limitation).7 A questionnaire based on patients’ reports of their illness is therefore likely to be skewed towards impairments only and not activity limitation. The SSI, however, contains symptoms such as feeling tired, falling asleep, and inability to concentrate throughout the day, all of which may limit the patient’s activity. The simplest summary of the SSI, and the one that is easiest to use in the clinic, is the sum of the scores on all 25 items, which measures the overall severity of the patient’s problems. The principal components analysis found that the important variation in the 261 patients studied could be described by three components. The first and most important component was effectively the total score of the items on the SSI, which essentially validates the use of the total score as the primary summary of the SSI. This total score is recommended for routine clinical use and audit purposes. The second component contrasts family and social problems with work-related problems, and may be a useful additional index of change, particularly in a research context. The third component contrasts physical problems and embarrassment. While the third component appears to bear a sensible interpretation, it explains only 6% of the total variation, and may thus prove to be less useful in future studies. Its value therefore needs to be kept under review as clinical experience of the SSI increases. The questionnaire comprises 25 items and we have not found this too onerous to administer, nor have our patients found it too long. However, if a shortened version were needed, perhaps for survey or epidemiological study, then a reduced version of the questionnaire could be contemplated, albeit at the loss of some information. If the user were prepared to sacrifice the PHYSEMB component, then only the 13 items required for the computation of SOCWK need be administered. The sum of these items is highly correlated with the total score on the full questionnaire (r ⫽ 0.89) and could be used as a surrogate for it. Several methods have been described for assessing various consequences of snoring and/or its treatment. The most commonly used, the Epworth Sleepiness Scale, was developed to measure daytime sleepiness, particularly in patients with obstructive sleep apnea. The ESS does not, however, consider other symptoms associated with snoring and therefore does not provide a comprehensive assessment of the patients’ problems due to snoring. Linear and visual analogue scores have been used to assess the outcome of snoring surgery but this simple method of assessment, which examines only the patient’s or their partner’s impression of the severity of their snoring,8,9 is not validated. Of previously described assessment tools, the “snoring scale score”10 is based on a questionnaire about the snoring noise characteristics, but does not address related
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symptoms. The Glasgow Benefit Inventory (GBI) has been developed for use in otorhinolaryngological surgery and has been used to examine outcome after procedures such as middle ear surgery, cochlear implantation, rhinoplasty, and tonsillectomy. It has been used to evaluate outcome after laser palatoplasty and uvulopalatopharyngoplasty.11 The GBI is a patient-oriented questionnaire and may be used to assess change in general health status from intervention, rather than the specific aspects of the underlying condition, such as habitual snoring. The Berlin questionnaire12 is a physician-derived sleep tool to identify sleep apnea, composed in 1996 by 120 American and German pulmonary and primary care physicians at a conference on sleep in primary care. The questions were chosen to identify factors that have been shown to predict sleep-disordered breathing such as snoring behavior, daytime somnolence or fatigue, and the presence or absence of obesity and hypertension. The Snore Outcomes Survey (SOS) is another recently described questionnaire to evaluate patients with snoring.13 It was developed as a self-report outcome measure of patients with sleep-disordered breathing. The items were chosen by an expert panel, however, and comprise only 8 questions that relate to the patient’s snoring severity, interference with normal sleep or energy levels, and the effect of snoring on their sleeping partner. Five of the top 10 items of the SSI (Table 1) have no comparable component in the SOS—I am embarrassed by my snoring; Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home; I am embarrassed to stay overnight with friends or relatives; I feel depressed because I cannot do anything about my snoring; I have a dry mouth or throat. The SSI demonstrated significant change in patients undergoing LAUP, indicating that it can be a useful tool in outcomes research. There was also strong evidence that the first and second principal components changed after LAUP. There was no evidence in the present sample that LAUP had any effect on the third component, which is associated with physical symptoms. The SSI has the unique advantage of providing patients’ perspectives in the results of their treatment.
CONCLUSION The application of the SSI in 261 patients has shown it to be a useful tool in snoring outcomes research. It is valid, reliable, and sensitive to change after intervention. It provides a readily computed total severity score, appropriate for routine clinical use in all clinical attenders, and two subscales reflecting Social-Work issues and Physical-Embarrassment, which may be of particular interest in clinical research. The SSI is the only available questionnaire to provide a comprehensive view of patients’ symptoms due to snoring.
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Otolaryngology–Head and Neck Surgery, Vol 134, No 1, January 2006
REFERENCES 1. Ohayon MM, Guilleminault C, Priest RG, et al. Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample. Br Med J 1997;314:860 –3. (Grade B). 2. Johns MW. A new method for measuring daytime sleepiness: The Epworth sleepiness scale. Sleep 1991;14:540 –5. (Grade B). 3. Barcham LJ, Stephens SDG. The use of an open-ended problems questionnaire in auditory rehabilitation. Br J Audiol 1980;14:49 –54. (Grade B). 4. Scott S, Robinson K, Ah-See K, et al. Disharmony due to habitual snoring: husband versus wife or doctor versus patient? (Abstract) Clin Otolaryngol 1998;23:270 –1. (Grade B). 5. Scott S, Ah-See K, Richardson H, et al. A comparison of the patient and physician perception of the problems of habitual snoring. Clin Otolaryngol 2003;28:18 –21. (Grade B). 6. Armitage P, Berry G, Matthews JNS. Statistical Methods in Medical Research. Oxford: Blackwell’s; 2002. Oxford. p. 458. (Grade D). 7. Scott S, Wilson JA, Mackenzie K. Patient-reported problems
8.
9.
10.
11.
12.
13.
associated with dysphonia. Clin Otolaryngol 1997;22:37– 40. (Grade B). Sharp JF, Jalaludin M, Murray JAM, et al. The uvulopalatopharyngoplasty operation: the Edinburgh experience. J Roy Soc Med 1990;83: 569 –70. (Grade C). Morar P, Nandapalan V, Lesser THJ, et al. Musosal-strip/uvulectomy by the CO2 laser as a method of treating simple snoring. Clin Otolaryngol 1995;20:308 –11. (Grade B). Lim PVH, Curry AR. A new method for evaluating and reporting the severity of snoring. J Laryngol Otol 1999;113:336 – 40. (Grade B). Richardson HC, Prichard AJN. Comparing the outcome of two surgical treatments for snoring using a patient-oriented measure of benefit. Clin Otolaryngol 1997;22:459 – 62. (Grade B). Netzer NC, Stoohs RA, Netzer CM, et al. Using the Berlin Questionnaire to identify patients at risk for the sleep apnea syndrome. Ann Int Med 1999;131:485–91. (Grade B). Glicklich RE, Wang P. Validation of the Snore outcomes survey for patients with sleep-disordered breathing. Arch Otolaryngol Head Neck Surg 2002;128:820 – 4. (Grade B).
Douglas et al
The Development of a Snoring Symptoms . . .
62.e1
APPENDIX SNORING SYMPTOMS INVENTORY Name. .......................................................................Date............................. Hospital Number (if known) ................................................Date of Birth.......... PLEASE ANSWER THE FOLLOWING STATEMENTS WITH YOUR FIRST IMPRESSION (please tick) Strongly agree 1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Agree
Neither
Disagree
Agree
Neither
Disagree
Strongly disagree
My sleep is disturbed My family complains about my snoring I feel tired I am concerned about disturbing my partner’s sleep or the sleep of others in the home I have a dry mouth or throat I am embarrassed when I stay overnight with friends or relatives I have a blocked nose Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home I am concerned that my snoring puts a strain on my personal relationship(s) I worry about falling asleep whilst driving I am embarrassed when I am on holiday or staying in hotels I feel bad tempered and irritable I sometimes fall asleep during the day I have a sore throat My sex life has been affected by my snoring I have problems concentrating on my work My neighbours complain about my snoring I am unable to concentrate during the day I lack self-confidence I have a choking feeling I feel depressed because I cannot do anything about my snoring I get headaches I have problems breathing I feel frightened of going to sleep I am embarrassed by my snoring Strongly agree
Score: Strongly agree ⫽ 4, Agree ⫽ 3, Neither ⫽ 2, Disagree ⫽ 1, Strongly disagree ⫽ 0 TOTAL ⴝ ...............
Strongly disagree
ORIGINAL RESEARCH
The Development of a Snoring Symptoms Inventory Susan A. Douglas, FRCS-Ed, FRCS (ORL), Simon Webster, MMathStat, Mohammed Reda El Badawey, MD, FRCS (ORL), Michael Drinnan, PhD, John N. S. Matthews, MA, PhD, G. John Gibson, BSc, MD, FRCP, FRCP-Ed, and Janet A. Wilson, MD, FRCS-Ed, FRCS, Nottingham and Newcastle upon Tyne, United Kingdom OBJECTIVE: To develop a patient-derived snoring questionnaire, the Snoring Symptoms Inventory (SSI), and explore its structure and relationship to the Epworth Sleepiness Scale (ESS); and to assess the sensitivity of the SSI to change. STUDY DESIGN AND SETTING: The SSI was developed from an open-ended questionnaire given to 120 habitual snorers. The 25 symptoms reported compose the SSI. This study examines 261 subsequent snorers assessed between April 1998 and August 2002, who completed both the SSI and the ESS. Fifty-five of them underwent laser uvulopalatoplasty and their preoperative and postoperative SSI results were compared. RESULTS: The total SSI score is the key outcome derived. Principal component analysis identified two further dimensions, one contrasting family/social with work-related problems and another comparing physical problems with embarrassment. The total score correlated weakly with the ESS. Laser uvulopalatoplasty significantly reduced patients’ overall symptom severity and family and socially related problems. CONCLUSION: The SSI is a comprehensive and sensitive measure for assessing snoring, making it a useful clinical outcome tool for snoring treatment. SIGNIFICANCE: The SSI is a new, useful snoring questionnaire. EBM rating: B-2b © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved.
From The Queen’s Medical Centre, Nottingham (Dr Douglas), The University of Newcastle upon Tyne (Mr Webster and Drs Drinnan, Matthews, Gibson, and Wilson), and ⫹The Freeman Hospital, Newcastle upon Tyne (Dr El Badawey). Presented at The British Association of Otolaryngology–Head and Neck Surgery, May 2002 and at the Annual Meeting of the American
S
noring is a ubiquitous condition and has been found to increase in frequency with age. In a telephone survey in the United Kingdom, 40.3% of the respondents reported snoring, with a prevalence of snoring increasing with age up to 55 years and also higher in men than women.1 Snorers are commonly overweight1 and frustrated by the social consequences of their noisy night-time resonance, but other symptoms are frequently variable. The most commonly used questionnaire in snoring patients is the Epworth Sleepiness Scale (ESS),2 but this focuses only on daytime somnolence and does not address the other consequences of snoring. It has been shown that questionnaires based on information obtained from patients may give a more accurate view of the symptoms than those designed exclusively by clinicians.3 Emphasis on the patients’ point of view enables the otolaryngologist to judge therapy in a manner that more closely reflects the way in which patients assess their own health. Reliable and sensitive self-report measures for snoring are currently lacking, which makes assessment of the outcomes of snoring surgery haphazard: the patient’s and partner’s self report are vital in the evaluation of snoring therapy, yet many otherwise well-designed studies report only a summary outcome such as visual analogue scores of a few items. There is a need for a snoring questionnaire that provides a comprehensive view of the consequent symptoms, and which is responsive to change after intervention. Academy of Otolaryngology–Head and Neck Surgery, Orlando, FL, September 21-24, 2003. Reprint requests: Susan Douglas, The Queens Medical Centre, Derby Road, Nottingham NG7 2UH, UK. E-mail address: [email protected].
0194-5998/$32.00 © 2006 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.09.006
Douglas et al
The Development of a Snoring Symptoms . . .
In our previous study4,5 120 habitual snorers were asked to list in an open fashion all the problems they had as a result of snoring. The study compared the symptoms as reported by the patient and the otolaryngologist. Otolaryngologists were more likely to record diurnal somnolence, sleep apnea, and relationship problems as the main symptoms of snorers, whereas habitual snorers more often cited disturbance of others’ sleep, irritability, and physical symptoms such as a dry mouth, breathing difficulty, lethargy, and choking.
AIMS The aims of the present study were: 1) to determine the principal factors measured by the Snoring Symptoms Inventory (SSI) and the relationship, if any, of these factors to the ESS; and 2) to establish the sensitivity to change of the SSI.
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METHODS The symptoms reported by the patients in our previous open-ended questionnaire were collated in the form of a 25-item snoring questionnaire—the Snoring Symptoms Inventory (SSI). The answer to each question had a 5-point severity scale, where 0 ⫽ strongly disagree, 1 ⫽ disagree, 2 ⫽ neither agree nor disagree, 3 ⫽ agree, 4 ⫽ strongly agree (see Appendix). Patients attending a snoring clinic between April 1998 and August 2002 were asked to complete the Snoring Symptoms Inventory and the Epworth Sleepiness Scale. Complete data sets were available for 261 patients, 200 males and 61 females, with an age range of 24 to 69 years (mean age 43.6 years). As larger scores indicated a more severe problem with snoring, the primary outcome of the questionnaire is the total of the 25 scores, ie, a value between 0 and 100, with 0
Table 1 Summaries of the responses to each question on the SSI in 261 habitual snorers Item 1* 2* 3* 4*
5* 6* 7 8*
9* 10 11 12 13 14 15 16 17 18 19 20 21* 22 23 24 25*
My sleep is disturbed My family complains about my snoring I feel tired I am concerned about disturbing my partner’s sleep or the sleep of others in the home I have a dry mouth or throat I am embarrassed when I stay overnight with friends or relatives I have a blocked nose Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home I am concerned that my snoring puts a strain on my personal relationship(s) I worry about falling asleep whilst driving I am embarrassed when I am on holiday or staying in hotels I feel bad tempered and irritable I sometimes fall asleep during the day I have a sore throat My sex life has been affected by my snoring I have problems concentrating on my work My neighbors complain about my snoring I am unable to concentrate during the day I lack self-confidence I have a choking feeling I feel depressed because I cannot do anything about my snoring I get headaches I have problems breathing I feel frightened of going to sleep I am embarrassed by my snoring
Mean score
Median score
Lower quartile
Upper quartile
2.77 3.24 2.79 3.72
3.0 4.0 3.0 4.0
2.0 3.0 2.0 4.0
4.0 4.0 3.5 4.0
2.59 2.84
3.0 3.0
2.0 2.0
3.0 4.0
2.38 2.89
3.0 3.0
1.0 2.0
3.0 4.0
3.25
4.0
3.0
4.0
1.20 2.45
1.0 3.0
0.0 2.0
2.0 3.0
2.44 2.51 1.81 2.32 1.79 1.27 1.71 1.49 1.76 2.56
3.0 3.0 2.0 3.0 2.0 1.0 2.0 1.0 2.0 3.0
2.0 2.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 2.0
3.0 3.0 3.0 3.0 3.0 2.0 3.0 2.0 3.0 3.0
1.98 2.13 1.40 3.10
2.0 2.0 1.0 3.0
1.0 1.0 1.0 3.0
3.0 3.0 2.0 4.0
For every question the minimum and maximum scores reported were 0 and 4. * ⫽ The 10 items with the largest mean scores.
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Otolaryngology–Head and Neck Surgery, Vol 134, No 1, January 2006 Fifty-five of these patients underwent laser uvulopalatoplasty (LAUP) and their preoperative and postoperative SSI data were compared in order to assess the questionnaire’s sensitivity to change.
RESULTS Total Score
Figure 1 Histogram of the total score for the SSI from 261 habitual snorers.
corresponding to no problems with snoring. The distribution of the total score, and its relationship with the age and sex of the patient and with the ESS, were described using standard statistical methods: histograms, scatter plots, t tests, and regression. Although each respondent gives 25 responses, we hypothesized that there are likely to be links between these different responses, such that there are, in fact, fewer separate aspects to the patient’s problems. These links will be reflected by common patterns in his or her response. The principal component analysis uncovers these common patterns by exploring the deeper structure of the correlation matrix of the responses. This also tells us if these links account for a substantial proportion of the total variation of the responses. Each link or component is reported as a linear combination of the scores on the individual questions. This method produces useful information if 1) most of the variation in the scores can be described by a few components and 2) the nature of the linear combinations permits a simple interpretation of the meaning of the score. For more details see “Statistical methods in medical research.”6 The relationships between the components and the total score of the ESS were also explored. Cronbach’s alpha statistic was calculated as a measure of the reliability of the questionnaire.
The means, medians and quartiles for the responses from each question are listed in Table 1. The histogram of the total score is shown Figure 1. The mean, standard deviation, and 95% confidence interval (the interval which contains 95% of the population) are shown in Table 2 for the total score overall and separately for men and women. The difference in means between males and females is 5.13 (P ⫽ 0.005, 95% confidence interval 1.56, 8.69), with the scores slightly higher for females. There is no evidence of a relationship with age (Pearson correlation ⫽ ⫺0.06, P ⫽ 0.34) but clear evidence that the total score increases with increasing ESS.
Principal Components Analysis The principal components analysis identified three components, which explain most variation: ⫺21%, 11%, and 6% respectively of the total variation (Table 3). Questions with large positive coefficients will give positive values on the component, in contrast to questions with large negative values, which will tend to give negative values to the component. Those questions associated with the numerically large coefficients dominate the component; important weightings are taken as coefficients greater than 0.15 for positive items, less than ⫺0.15 for negative items. The first component has coefficients that are all positive and of broadly similar size. This gives a component with properties very similar to the total score used above: the correlation between the score on the first component and the total score is 0.98 (P ⬍ 0.0001). In other words, the first component is effectively a measure of the overall severity of the symptoms recorded in the SSI. The second component gives large positive weighting to items 2, 4, 6, 8, 9, 11, 15, 21, and 25. These are all connected with the effects of snoring on other family
Table 2 Summary values for total scores, Social-Work and Physical-Embarrassment scores in 261 snorers Variable
Mean
SD
Total score Total score n ⫽ 61 females Total score n ⫽ 200 males Social-Work Physical-Embarrassment
58.4 62.3 57.2 17.56 8.42
12.5 13.4 12.0 6.37 4.45
95% Confidence interval 33.8, 36.0, 33.6, 5.09, ⫺0.30,
83.0 88.6 80.8 30.04 17.14
Correlation with ESS 0.39, 0.44, 0.38, ⫺0.18, 0.10,
P P P P P
⬍ ⬍ ⬍ ⫽ ⫽
0.0005 0.0005 0.0005 0.004 0.10
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Table 3 Coefficients of the first three components from the principal component analysis Component Item
Statement
1
2
3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Sleep disturbed Family complains about snoring Feel tired Partner/others in house has sleep disturbed Dry mouth or throat Embarrassed when staying with friends Blocked nose Sleep separately from partner sometimes Strain on personal relationships Worry about falling asleep driving Embarrassed when on holiday/in hotels Bad-tempered and irritable Fall asleep during day Sore throat Sex life affected by snoring Problems concentrating on work Neighbors complain about snoring Unable to concentrate during day Lack self-confidence Choking feeling Cannot do anything about snoring Headaches Problems with breathing Frightened of going to sleep Embarrassed by snoring Associated eigenvalue
0.21 0.03 0.25 0.09 0.14 0.19 0.10 0.03 0.11 0.14 0.22 0.25 0.17 0.18 0.10 0.24 0.17 0.25 0.20 0.17 0.18 0.20 0.20 0.22 0.20 5.40
⫺0.07 0.17 ⫺0.21 0.33 0.04 0.22 ⫺0.07 0.28 0.29 ⫺0.14 0.20 ⫺0.05 ⫺0.15 ⫺0.02 0.19 ⫺0.19 0.09 ⫺0.19 ⫺0.13 ⫺0.03 0.27 ⫺0.14 ⫺0.13 0.05 0.30 2.67
⫺0.08 0.25 ⫺0.02 ⫺0.04 0.33 ⫺0.32 0.33 0.22 0.08 ⫺0.08 ⫺0.15 0.03 ⫺0.05 0.22 0.08 0.04 ⫺0.10 ⫺0.01 ⫺0.08 0.21 ⫺0.02 ⫺0.10 0.15 ⫺0.01 ⫺0.29 1.42
Note for Component 2, Social-Work, and 3, Physical-Embarrassment: important positive weightings in bold, important negative weightings in italic.
members, embarrassment caused by snoring, and feeling unable to do anything about the problem. Large negative values are given to items 3, 13, 16, and 18, which are all related to tiredness and work-related problems. This component will therefore be large (positive) for patients where social and family difficulties are the dominant problem caused by their snoring and small (negative) for those for whom work-related problems and tiredness dominate. The third component gives large positive weighting to items 2, 5, 7, 8, 14, 20, and 23. Items 2 and 8 relate to the disturbance caused by snoring, while all the other items are physical problems suffered by the patient. Large negative weights are given to items 6, 11, and 25, which are all connected with embarrassment. The presence of items 2 and 8 makes interpretation slightly awkward but essentially this component contrasts physical problems with embarrassment: for patients with large positive values, the physical problems of their snoring dominate their embarrassment, while the opposite is true for patients with large negative values.
Calculating Component Scores and Simplified Scores The exact score of a patient on each of the three components (product of the item score and its weighting coefficient; Table 3, Fig 2) is impractical to compute in a clinic. The total score has been shown adequately to reproduce the information in the first component. The Social-Work (SOCWK) component is mirrored by the sum of scores on items 2, 4, 6, 8, 9, 11, 15, 21, and 25 minus the sum of scores returned on 3, 13, 16, and 18. The Physical-Embarrassment (PHYSEMB) component is likewise derived from the sum of 2, 5, 7, 8, 14, 20, and 23 minus the sum of scores on items 6, 11, and 25. These scores are easily computed alternatives to the second and third components respectively. This is demonstrated by the high correlations: Social-Work has a correlation of 0.963 with the second component and Physical-Embarrassment a correlation of 0.944 with the third component. Summary quantities for these scores, including their correlation with ESS, are given in Table 2.
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Otolaryngology–Head and Neck Surgery, Vol 134, No 1, January 2006 patients undergoing LAUP had more severe symptoms, centered on social and family or work. There is strong evidence that both the total score and SOCWK were lower after LAUP (Table 4), whereas the PHYSEMB domain was not statistically different, suggesting the operation has less impact on physical symptoms.
DISCUSSION
Figure 2 Distribution of the Social-Work component and the Physical-Embarrassment component scores in 261 patients.
Questionnaire Reliability The Cronbach’s alpha for the 25 questions of the SSI was 0.81, which demonstrates good reliability.
Change in SSI After Laser Uvulopalatoplasty Fifty-five of the 261 patients whose data have been described above underwent laser uvulopalatoplasty. The preoperative means of total SSI score, SOCWK score, and PHYSEMB score for this subset of patients (83.4, 24, and 11.3 respectively, Table 4) were all larger than the corresponding means for the group as a whole. Thus the
The development of the Snoring Symptoms Inventory gives insight into the various types of symptoms associated with snoring, and is not confined to the effects of sleep apnea. These symptoms are sleep-related, physical, and psychosocial and relationship difficulties. In the original derivation of the SSI, we found that otolaryngologists were more likely to report diurnal somnolence and relationship problems as the main symptoms of habitual snorers, whereas the patients more often cited disturbance of the sleep of others, and lethargy.5 The 10 items with the highest reported scores in the SSI for our group of patients also demonstrated concern about disturbing the sleep of others or that snoring put a strain on personal relationships and embarrassment about snoring (Table1). These features also influenced each of the first three principal components. This reinforces the different viewpoints held by the physician and the patient and that these fundamental differences may mold the patients’ perspective of their problem and treatment. For example, after treatment a patient may not show a very marked reduction in snoring intensity measured in decibels, but if the reduction is sufficient to allow that individual’s partner to sleep in the same bed, the patient is likely to be satisfied with the result. The SSI enables us to assess the patient from the viewpoint of a wider symptom range and thus to achieve a comprehensive analysis of the patient’s problem. The International Classification of Functioning, Disability and Health describes levels of disability with impairments as significant deviation or loss of body function or structures and activity limitation as difficulties experienced in executing certain activities. It has been demonstrated that patients in a hospital clinic often describe problems associated with impairments in preference to those that demonstrate limitation of activity. The patient may report disturbed sleep (impairment) but not report that he is tired throughout the day and
Table 4 Summary of mean SSI scores pre- and post-LAUP Variable
Preop score
Postop score
Mean change preop–postop
95% confidence interval
P
Total SSI score Social-Work Physical-Embarrassment
83.4 24.0 11.3
65.8 15.8 10.9
17.6 8.3 0.4
13.0, 22.1 5.9, 10.7 ⫺0.8, 1.6
⬍0.0005 ⬍0.0005 0.52
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The Development of a Snoring Symptoms . . .
is therefore unable to get a job (activity limitation).7 A questionnaire based on patients’ reports of their illness is therefore likely to be skewed towards impairments only and not activity limitation. The SSI, however, contains symptoms such as feeling tired, falling asleep, and inability to concentrate throughout the day, all of which may limit the patient’s activity. The simplest summary of the SSI, and the one that is easiest to use in the clinic, is the sum of the scores on all 25 items, which measures the overall severity of the patient’s problems. The principal components analysis found that the important variation in the 261 patients studied could be described by three components. The first and most important component was effectively the total score of the items on the SSI, which essentially validates the use of the total score as the primary summary of the SSI. This total score is recommended for routine clinical use and audit purposes. The second component contrasts family and social problems with work-related problems, and may be a useful additional index of change, particularly in a research context. The third component contrasts physical problems and embarrassment. While the third component appears to bear a sensible interpretation, it explains only 6% of the total variation, and may thus prove to be less useful in future studies. Its value therefore needs to be kept under review as clinical experience of the SSI increases. The questionnaire comprises 25 items and we have not found this too onerous to administer, nor have our patients found it too long. However, if a shortened version were needed, perhaps for survey or epidemiological study, then a reduced version of the questionnaire could be contemplated, albeit at the loss of some information. If the user were prepared to sacrifice the PHYSEMB component, then only the 13 items required for the computation of SOCWK need be administered. The sum of these items is highly correlated with the total score on the full questionnaire (r ⫽ 0.89) and could be used as a surrogate for it. Several methods have been described for assessing various consequences of snoring and/or its treatment. The most commonly used, the Epworth Sleepiness Scale, was developed to measure daytime sleepiness, particularly in patients with obstructive sleep apnea. The ESS does not, however, consider other symptoms associated with snoring and therefore does not provide a comprehensive assessment of the patients’ problems due to snoring. Linear and visual analogue scores have been used to assess the outcome of snoring surgery but this simple method of assessment, which examines only the patient’s or their partner’s impression of the severity of their snoring,8,9 is not validated. Of previously described assessment tools, the “snoring scale score”10 is based on a questionnaire about the snoring noise characteristics, but does not address related
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symptoms. The Glasgow Benefit Inventory (GBI) has been developed for use in otorhinolaryngological surgery and has been used to examine outcome after procedures such as middle ear surgery, cochlear implantation, rhinoplasty, and tonsillectomy. It has been used to evaluate outcome after laser palatoplasty and uvulopalatopharyngoplasty.11 The GBI is a patient-oriented questionnaire and may be used to assess change in general health status from intervention, rather than the specific aspects of the underlying condition, such as habitual snoring. The Berlin questionnaire12 is a physician-derived sleep tool to identify sleep apnea, composed in 1996 by 120 American and German pulmonary and primary care physicians at a conference on sleep in primary care. The questions were chosen to identify factors that have been shown to predict sleep-disordered breathing such as snoring behavior, daytime somnolence or fatigue, and the presence or absence of obesity and hypertension. The Snore Outcomes Survey (SOS) is another recently described questionnaire to evaluate patients with snoring.13 It was developed as a self-report outcome measure of patients with sleep-disordered breathing. The items were chosen by an expert panel, however, and comprise only 8 questions that relate to the patient’s snoring severity, interference with normal sleep or energy levels, and the effect of snoring on their sleeping partner. Five of the top 10 items of the SSI (Table 1) have no comparable component in the SOS—I am embarrassed by my snoring; Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home; I am embarrassed to stay overnight with friends or relatives; I feel depressed because I cannot do anything about my snoring; I have a dry mouth or throat. The SSI demonstrated significant change in patients undergoing LAUP, indicating that it can be a useful tool in outcomes research. There was also strong evidence that the first and second principal components changed after LAUP. There was no evidence in the present sample that LAUP had any effect on the third component, which is associated with physical symptoms. The SSI has the unique advantage of providing patients’ perspectives in the results of their treatment.
CONCLUSION The application of the SSI in 261 patients has shown it to be a useful tool in snoring outcomes research. It is valid, reliable, and sensitive to change after intervention. It provides a readily computed total severity score, appropriate for routine clinical use in all clinical attenders, and two subscales reflecting Social-Work issues and Physical-Embarrassment, which may be of particular interest in clinical research. The SSI is the only available questionnaire to provide a comprehensive view of patients’ symptoms due to snoring.
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REFERENCES 1. Ohayon MM, Guilleminault C, Priest RG, et al. Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample. Br Med J 1997;314:860 –3. (Grade B). 2. Johns MW. A new method for measuring daytime sleepiness: The Epworth sleepiness scale. Sleep 1991;14:540 –5. (Grade B). 3. Barcham LJ, Stephens SDG. The use of an open-ended problems questionnaire in auditory rehabilitation. Br J Audiol 1980;14:49 –54. (Grade B). 4. Scott S, Robinson K, Ah-See K, et al. Disharmony due to habitual snoring: husband versus wife or doctor versus patient? (Abstract) Clin Otolaryngol 1998;23:270 –1. (Grade B). 5. Scott S, Ah-See K, Richardson H, et al. A comparison of the patient and physician perception of the problems of habitual snoring. Clin Otolaryngol 2003;28:18 –21. (Grade B). 6. Armitage P, Berry G, Matthews JNS. Statistical Methods in Medical Research. Oxford: Blackwell’s; 2002. Oxford. p. 458. (Grade D). 7. Scott S, Wilson JA, Mackenzie K. Patient-reported problems
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associated with dysphonia. Clin Otolaryngol 1997;22:37– 40. (Grade B). Sharp JF, Jalaludin M, Murray JAM, et al. The uvulopalatopharyngoplasty operation: the Edinburgh experience. J Roy Soc Med 1990;83: 569 –70. (Grade C). Morar P, Nandapalan V, Lesser THJ, et al. Musosal-strip/uvulectomy by the CO2 laser as a method of treating simple snoring. Clin Otolaryngol 1995;20:308 –11. (Grade B). Lim PVH, Curry AR. A new method for evaluating and reporting the severity of snoring. J Laryngol Otol 1999;113:336 – 40. (Grade B). Richardson HC, Prichard AJN. Comparing the outcome of two surgical treatments for snoring using a patient-oriented measure of benefit. Clin Otolaryngol 1997;22:459 – 62. (Grade B). Netzer NC, Stoohs RA, Netzer CM, et al. Using the Berlin Questionnaire to identify patients at risk for the sleep apnea syndrome. Ann Int Med 1999;131:485–91. (Grade B). Glicklich RE, Wang P. Validation of the Snore outcomes survey for patients with sleep-disordered breathing. Arch Otolaryngol Head Neck Surg 2002;128:820 – 4. (Grade B).
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APPENDIX SNORING SYMPTOMS INVENTORY Name. .......................................................................Date............................. Hospital Number (if known) ................................................Date of Birth.......... PLEASE ANSWER THE FOLLOWING STATEMENTS WITH YOUR FIRST IMPRESSION (please tick) Strongly agree 1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Agree
Neither
Disagree
Agree
Neither
Disagree
Strongly disagree
My sleep is disturbed My family complains about my snoring I feel tired I am concerned about disturbing my partner’s sleep or the sleep of others in the home I have a dry mouth or throat I am embarrassed when I stay overnight with friends or relatives I have a blocked nose Because of my snoring, I sometimes have to sleep in a separate room to my partner or others in the home I am concerned that my snoring puts a strain on my personal relationship(s) I worry about falling asleep whilst driving I am embarrassed when I am on holiday or staying in hotels I feel bad tempered and irritable I sometimes fall asleep during the day I have a sore throat My sex life has been affected by my snoring I have problems concentrating on my work My neighbours complain about my snoring I am unable to concentrate during the day I lack self-confidence I have a choking feeling I feel depressed because I cannot do anything about my snoring I get headaches I have problems breathing I feel frightened of going to sleep I am embarrassed by my snoring Strongly agree
Score: Strongly agree ⫽ 4, Agree ⫽ 3, Neither ⫽ 2, Disagree ⫽ 1, Strongly disagree ⫽ 0 TOTAL ⴝ ...............
Strongly disagree