Evaluation of a nasal surgical questionnaire designed for monitoring surgical outcomes and comparing different techniques

Clinically important estimates of improvement after septoplasty

OBJECTIVE

A statistically significant improvement in nasal obstruction ratings following septoplasty is not necessarily clinically important. This study aimed to establish useful measures of septoplasty success, namely the minimal clinically important difference and the desirable clinically important difference.

METHODS

Patients rated nasal obstruction on a 0-100 visual analogue scale pre-operatively and at 5.5 months post-operatively. Global outcome rating (completely, much, or somewhat improved, unchanged or worse) served as the anchor post-operatively. Minimal clinically important difference is the visual analogue scale value between 'somewhat improved' and 'unchanged', and the desirable clinically important difference is that between 'much' and 'somewhat improved'.

RESULTS

Statistically significant improvement in visual analogue scale scores was not clinically important. The minimal clinically important difference (daytime value of 9.5) represented 15.1 per cent improvement and the desirable clinically important difference (daytime value of 28.5) represented 45.2 per cent, without gender or age differences.

CONCLUSION

Clinical success can be defined using a minimal clinically important difference of 15 per cent improvement over a patient's baseline value. Other studies' ratings of 'satisfactory' outcome coincided with a desirable clinically important difference of 45 per cent over baseline. These values are suggested as relevant indicators of septoplasty success.

Good correlation between visual analogue scale and numerical rating scale in the assessment of nasal obstruction

OBJECTIVE

Results from telephone interviews may be needed to supplement those from mailed questionnaires when response rates are inadequate. This study assessed the correlation between visual analogue scale ratings used in mailed questionnaires and numerical rating scale scores used in telephone interviews.

METHODS

Patients scheduled for nasal septal surgery routinely respond to a visual analogue scale of obstruction during the day and at night. In this study, they were also asked to verbally rate their sense of obstruction using whole numbers.

RESULTS

There was no significant difference between visual analogue scale and numerical rating scale obstruction scores.

CONCLUSION

Ratings of nasal obstruction obtained with a numerical rating scale in telephone interviews are comparable to visual analogue scale scores in mailed questionnaires.

Evaluation of non-response in quality control of nasal septal surgery

OBJECTIVE

Questionnaires are often used to assess the results of nasal septoplasty, but response rates vary widely. The possible bias caused by non-responders was evaluated to determine the validity of questionnaire results.

METHODS

Post-operative questionnaires employing visual analogue scales for nasal obstruction were mailed to 182 patients. The 62 non-responders (34.1 per cent) were contacted by telephone, 58 (93.5 per cent) of whom were contactable and responded orally to the questionnaire.

RESULTS

Non-responders were younger, but no different from responders with regard to gender, smoking habits or allergies. Post-operative visual analogue scale obstruction scores were slightly, but not statistically, higher in non-responders. However, because non-responders' pre-operative scores were lower, obstruction scores improved less than in responders. The main reason for not responding was forgetfulness. Some would have preferred an electronic version of the questionnaire.

CONCLUSION

Although post-operative obstruction scores did not differ between the groups, nasal obstruction scores improved more among responders than non-responders. Thus, low response rates may cause bias.

Evaluation of the Nasal Surgical Questionnaire for Monitoring Results of Septoplasty

Monitoring the results of surgery is important. The otorhinolaryngology department of our hospital currently uses preoperative and postoperative versions of the Nasal Surgical Questionnaire (NSQ) for continuous evaluation of nasal septoplasty. In this study, 55 patients undergoing septoplasty answered the preoperative version twice to assess the NSQ's test-retest precision, and 75 patients answered the preoperative questionnaire before and the postoperative one 6 months after surgery to evaluate the NSQ's ability to detect change in symptoms following surgery. Both the pre- and postoperative versions of the NSQ use separate visual analogue scales (VAS) to assess nasal obstruction during the day, at night, and during exercise. Other nasal symptoms are graded as secondary outcomes using 4-point Likert scales. The mean VAS scores for the two preoperative obstruction ratings were not significantly different. The scores were significantly higher than in a normal population. There were also significant differences between preoperative and postoperative ratings. The mean pre- and postoperative scores at night for those who reported complete improvement were 66.1 and 8.4, substantial improvement 74.5 and 24.2, and no improvement 83.3 and 76.4. The NSQ reliably assesses nasal symptoms in patients and may be useful for both short and long term prospective studies of septoplasty.