Cost effectiveness of MRI diffusion in cholesteatoma follow-up

BACKGROUND

Eradication and follow-up of a cholesteatoma (a keratin mass in the ear) is mandatory because it is a slow growing but destructive disease with the risk of hearing loss, imbalance or facial nerve paralysis. Follow-up must be done because in about 20% there is a residual cholesteatoma.



OBJECTIVE(S)/RESEARCH QUESTION(S)

1. Are the hearing levels after three years of follow-up with annual diffusion-weighted MRI comparable to those after follow-up with second look surgery?

2. Is a diffusion-weighted MRI follow-up strategy cost-effective compared to second look surgery?

3.Are other outcome measures (residual and recurrent cholesteatoma, quality of life and adverse events) comparable between both follow-up strategies?



HYPOTHESIS

Diffusion-weighted MRI is a cost-effective follow-up strategy after primary cholesteatoma surgery compared to the usual care, 2nd look surgery with equal quality of care in terms of hearing, cholesteatoma detection rate, complications and quality of life.



STUDY DESIGN

Economic evaluation alongside a prospective multicenter randomized controlled trial with an intention-to-treat analysis plus additional observational study.



STUDY POPULATION(S)/DATASETS

153 patients of 16 years and older after primary or recurrent cholesteatoma surgery treatment with normal to mild conductive hearing loss.

INTERVENTION

Annual diffusion-weighted MRI during 3 consecutive years, starting 1 year after primary surgery.



STANDARD INTERVENTION TO BE COMPARED TO

Second look surgery 1 year after primary surgery and follow-up during 3 consecutive years.

OUTCOME MEASURES

1. The degree of hearing loss after 3 thee years of follow-up

2. The costs of three years follow-up

3. The number of 2nd look surgeries without cholesteatoma present (unnecessary surgical procedures)and the number of residual and recurrent cholesteatoma, health related quality of life and number of complications

SAMPLE SIZE CALCULATION/DATA ANALYSIS

To detect a clinically relevant difference of 8dB conductive hearing loss, the minimal number of participants needed after 3 year follow-up is: 122 (61 in each arm). Because of an expected drop-out of 20%, 153 patients will be included..

COST-EFFECTIVENESS ANALYSIS/ BUDGET IMPACT ANALYSIS

An economic evaluation will be performed from a societal as well as a healthcare perspective

Intervention costs of surgery and MRI will be estimated using a micro-costing approach.

Both a cost-effectiveness analysis in terms of the primary outcome (hearing) and a cost-utility analysis (QALYs) will be performed. Economic evaluations will be performed in accordance with the intention-to-threat principle

TIME SCHEDULE (months)

0-12 inclusion of participants

6-18 first intervention

30 two year follow-up and 85% of all interventions completed

34-48 start implementation, national and local meetings and guideline group

44-48 completion of the data gathering, analysis and publication

KEYWORDS

Cholesteatoma, MRI, Hearing, Cost-effectiveness, Quality of Life, QALY

Diffusion-weighted MRI is a cost-effective follow-up strategy after primary cholesteatoma surgery compared to the usual care, 2nd look surgery with equal quality of care in terms of hearing, cholesteatoma detection rate, complications and quality of life.

TIME SCHEDULE (months)

0-12 inclusion of participants

6-18 first intervention

30 two year follow-up and 85% of all interventions completed

34-48 start implementation, national and local meetings and guideline group

44-48 completion of the data gathering, analysis and publication

Only questionnaires will be extra for all patients
Half of the patients will undergo the standard care, which is a second look surgery intervention including one day hospitalization.

The other half will undergo each year a MRI scan of around 40 minutes

There are NO additional interventions which are part of the research, they are all part of the normal follow-up (like audiogram, otoscopy)