- Standard operating procedures: patient recruitment
During the enrolment phase, all patients admitted to the participating wards of the UPD
Bern will be screened in person. The screening will consist of a few questions regarding
sleep, implemented into the routine clinical interview at enrolment, and filling in the
insomnia severity index. Eligible patients will be contacted by study staff, informed
about the study, and invited to participate. For further information about the study, a
flyer containing the most important details will be given to the participants. The
screening and enrolment process will be standardized across the wards to minimize the
risk of selection bias.
- Standard operating procedures: data collection & data management Source data
verification Quality assurance: data validation & registry procedures
Data is recorded and collected in paper CRFs as source documents. ECRFs will be given as
an option for direct anonymized data entry from participants if feasible. The eCRFs will
be created and stored on the database RedCap which is a database recommended by the
Clinical Trial Unit Bern. Data entry from the source paper CRFs to eCRFs should only be
performed by authorized personnel and data should be consistent with the available source
documents. When this is not the case, a detailed explanation of the discrepancies should
be provided. The principal investigator should ensure the accuracy, completeness, and
timeliness of the data reported and sign off the completed eCRFs. In order to reflect the
current patient status throughout the study, eCRFs will be kept up to date. This means
that eCRFs should be completed no later than two weeks after a participant's visit and
that data entry not should be delayed unnecessarily.
Data edit checks will be implemented into the EDC (electronic data capture) system
(RedCap), limiting entries to appropriate, realistic values (e.g. not allowing future
dates, missing values etc.). Furthermore, selected data points are cross-checked for
plausibility with previously entered data for each individual participant. Before
database lock, each PI will validate the collected data from his site with his signature.
- Quality assurance: Site monitoring & auditing
On-site monitoring will be part of the quality control activities implemented for this
study. For the purposes of monitoring, the PI at the site will provide the monitor with
access to study documentation, patient records, facilities and any other resources
necessary. No site audits by the sponsor are planned for this study, but the sponsor
reserves the right to perform such an audit should it be considered necessary.
- Standard operating procedures: reporting of adverse events
AEs will be categorized concerning the type of the reaction, severity, relatedness to the
intervention, action taken, and outcome. Adverse events will be asked at every study
timepoint.
The frequency of occurrence of adverse events of different categories will be analysed
using descriptive statistics and compared between the two groups using Chi square tests.
The sponsor investigator will report to the Ethics Committee via BASEC device
deficiencies that could have led to serious adverse events if suitable action had not
been taken, intervention had not been made, or circumstances had been less fortunate
within 7 days
Sample size assessment A power analysis was conducted with G-Power. Assuming an alpha
error level of 0.05 (two-sided) and a power of 0.8, a total sample size of n=60 will be
sufficient to detect a medium effect (Cohen's d=0.65). This is a pilot trial with the
primary aim of collecting qualitative experience and preliminary efficacy data. A large
confirmatory trial will be conducted if the results of this pilot trial are encouraging.
Plan for missing data If a patient withdraws consent for further study participation, the
data collected up to the time point of withdrawal will be included in the study and no
further data will be collected. The data of withdrawn participants will not be anonymized
but will remain coded after analysis of the data set. For participants who discontinue
the study intervention but do not withdraw from participation in the study, study visits
and data collection will continue in the same way as for non-withdrawn participants.
Dropouts before start of treatment (i.e. non-starters) will be replaced by recruitment of
new participants. Multiple imputation will be used in case data are not available for
more than 5-10% of the sample.
- Standard operating procedures: Data analysis & statistical analysis plan Primary
Analysis
The primary outcome, i.e. the four overall scores of the ISI of all follow-up time-points
will be analyzed with a mixed effects linear model. The model will take into account the
hierarchical structure of the data: multiple ISI scores per patient and clusters
(cross-over). Because of the complexity of the data and the small number of clusters the
investigators assume that they will not be able to introduce random effects for patients
and clusters. However, the first approach will still be a linear mixed model with the
following co-variables: fixed intervention effect (TAU plus SLEEPexpert versus TAU plus
sleep monitoring), fixed baseline ISI score effect, random patient effect (multiple ISI
scores during follow-up), random cluster effect. Depending on model fit, the
investigators may need to simplify the model and modify the random effects. This model is
pre-specified and the rationale for switching will be made explicit. The analysis will be
made after all data has been collected by one of the principal investigators.
Secondary Analysis
Continuous outcomes (Brief Symptom Inventory, Beck Depression Inventory) will also be
analyzed by a mixed effects linear model using the same procedure used to estimate the
primary outcome. Binary outcome data will be analysed using mixed effect logistic
regression with odds-ratio as the effect measure. The number of hospitalizations will be
also analyzed by a mixed effects model.
Data dictionary The detailed data dictionary can be found in the study protocol in the
document section.
