Rationale
Surgical removal of palatal tonsils is among the most common ear, nose and throat operations in adults in Finland. The vast majority of these operations are done for recurrent and chronic tonsillitis. Internationally accepted guidelines for the treatment of these diseases are lacking and the indications for tonsil surgery are practice-based rather than evidence-based. The choice of the surgical technique further confuses the picture. The traditional surgical technique has been the total removal of tonsils (tonsillectomy, TE). The relatively recent introduction of partial resection of tonsils, namely tonsillotomy (TT), is suggested to have the benefits of less postoperative pain and smaller risk of post-operative hemorrhage as compared to TE. The relative efficacy of these two techniques to alleviate infective tonsillar diseases is still unclear.
Objectives
The main aim of this study is to obtain reliable evidence on, whether tonsil surgery improves the quality of life in adult patients suffering from recurrent or chronic tonsillitis, and whether the lighter TT would be as effective as TE. We will also compare the scores of a generic quality of life questionnaire as well as several other subjective and objective beneficial and harmful outcomes between the groups.
Methods
In this pragmatic multi-center randomized controlled trial, adult patients suffering from recurrent or chronic tonsillitis will be randomly allocated to three groups: tonsillotomy group (TT), tonsillectomy group (TE) and control group with watchful waiting (WW) in ratio 2:2:1. The patients in the surgical groups are blinded to the operation type (TT or TE). Our hypothesis is that both surgical treatments are more effective than watchful waiting in enhancing quality of life without significant risks (superiority assumption) and that TT is non-inferior to TE when the surgical groups are compared (non-inferiority assumption). Our principal outcome is disease-specific quality of life questionnaire score (Tonsillectomy Outcome Inventory (TOI)-14) at 6 months follow-up. We have validated this questionnaire in Finnish and explored the interpretation of the scores. Secondary outcomes have been listed in the Outcomes section.
Separate random allocation lists for the main research center (Oulu University Hospital) and for the four other centers collectively as well as for recurrent and for chronic tonsillitis will be used. Random permuted blocks is used with block size varying between 5 and 10. Based on our earlier study, the principal outcome, TOI-14 score, will most probably be left-truncated at zero and right-skewed. Therefore, both tobit-analysis and covariate analysis is used with log (1+y) transformation. The primary analysis has two phases. Firstly, the TOI-14 score in the combined surgical group (TT+TE) is compared to that in the WW group. Secondly, the score in the TT group is compared to that in the TE group. Effects will be estimated by adjusted mean differences in the log-transformed scores with 95% confidence intervals. Based on our earlier observational studies on the subject, the following covariates are included in the multivariable adjusted model: gender and baseline TOI-14 score together with stratification factors: enrolling center (Oulu vs. others) and main complaint (recurrent vs. chronic tonsillitis). In case there is missing data on the primary outcome, a multiple imputation method will be used. The analyses will be performed on an intention to treat basis. Per protocol analysis will be performed as sensitivity analysis and results from comparisons on secondary outcomes and subgroup analysis (main complaint) are used to generate hypothesis for future trials.
