Enrollment
Watch for changes
Introduction
Enrollment describes how patients join the study over space and time. In order to adapt to the level of available data, 4C Supply® supports different enrollment methods ranging from strongly simplified to highly granular.
Enrollment Levels
By setting an enrollment level, users can specify that enrollment rates should be interpreted as:
patients per site per month (default) or
patients per region per month.
To define an enrollment level, a column with header ‘Enrollment level’ must included in the demand configuration table, which accepts values:
Site (default)
Region
If a invalid entry is made, an error with the following message is shown:
Enrollment rate level '[value as entered]' couldn't be identified. Please use a value among ['Site', 'Region']. Level is set to 'Site'.
Example
Demand configuration
Single patient demand interval |
Enrollment and demand interval |
Enrollment simulations count |
Manual overage |
Enrollment level |
Confidence for site buffers |
---|---|---|---|---|---|
7 |
1 month |
50 |
0 |
Region |
97% |
Enrollment Level - Site
If the enrollment level is set to site, the 4C Supply® specification interpreter will evaluate specified enrollment rates as patients per site per month.
If the enrollment level is set to site, enrollment must be specified:
in the Site Groups Table (enrollment rate of each active site in the corresponding site group in every period) or
using an Enrollment Table (enrollment rate of each active site in the corresponding site group in the corresponding period).
If enrollment is specified using an Enrollment Table, column headers must be specified as site groups. If column headers are not specified as site groups, an error with the following message is shown:
No site group name found in [value as specified in enrollment table column header]. This column will be ignored. Consider modifying the enrollment rate level, currently set to Site."
Enrollment Level - Region
If the enrollment level is set to region, the 4C Supply® specification interpreter will evaluate enrollment rates as patients per region per month.
If the enrollment level is set to region, enrollment must be specified using an enrollment table (enrollment rate of the corresponding region in the corresponding period).
If the enrollment level is set to region and enrollment is defined in the site groups table, a warning with the following message is shown:
The enrollment should be specified per region per month. The column defining site groups enrollment rates will be ignored.
If enrollment is specified using an enrollment table, column headers must be specified as regions. If column headers are not specified as regions, an error with the following message is shown:
No region name found in [value as specified in enrollment table column header]. This column will be ignored. Consider modifying the enrollment rate level, currently set to Region.
If the enrollment level is set to region and multiple site groups are specified per region,
then the specified site groups are mapped in the calculation as closely as possible to enrollment groups low, medium and high:
if an enrollment group is specified which can’t be mapped to low, medium or high, then this group is considered as medium (e.g. “All” is mapped to “Medium”),
if an enrollment group is specified which doesn’t match groups low, medium or high, but contains one of the keywords is contained, it is mapped to the corresponding group (e.g. “very high” is mapped to “high”) and
the specified enrollment per cohort, region and period is split among the sites which are active in a period such that:
enrollment per site with enrollment group Medium = 2 * enrollment per site with enrollment group Low and
enrollment per site with enrollment group High = 3 * enrollment per site with enrollment group Low.
Enrollment specification
Enrollment specification can occur:
in the site groups table (specific enrollment rates per site group, but same enrollment rate for all periods) or
using an enrollment table (specific enrollment rates per site group and per period).
Enrollment definition in the site groups table
Enrollment can be defined in the site groups table. In this case, different enrollment rates can be applied for each site group which are the same for each enrollment period.
If enrollment is specified in the same specification in the site groups table and in an enrollment table, an error with the following message is shown:
PlannedEnrollment for [scenario description], [site group] in region [region] ([scenario description]), None has already been defined, probably in the site group table. Ignoring.
Enrollment definition using an enrollment table
Enrollment can be defined in a dedicated enrollment table. In this case, different enrollment rates can be applied
for each cohort,
for each site group or region and
for each enrollment period.
In studies without cohorts:
If enrollment level is site: there must be a column for each site group in the enrollment table
If enrollment level is region: there must be a column for each region in the enrollment table
In studies with cohorts:
If enrollment level is site: there must be a column for each cohort and site group in the enrollment table
If enrollment level is region: there must be a column for each cohort and region in the enrollment table
If any of the columns specified above are missing, no enrollment will be forecasted for the corresponding site group, cohort / site group combination, region or cohort / region combination.
If enrollment is defined in an enrollment table for a scenario with cohorts and the enrollment table column headers do not specify the cohort, an error with the following message is shown:
'NoneType' object has no attribute 'get_screening_duration'
Example
Enrollment table
Period start date |
CO_01 / RE_USA |
CO_01 / RE_GBR |
CO_01 / RE_GER |
CO_02 / RE_USA |
CO_02 / RE_GBR |
CO_02 / RE_GER |
1-Jan-21 |
0.1 |
|
|
|
|
|
1-Feb-21 |
0.2 |
0.1 |
0.1 |
|
|
|
1-Mar-21 |
0.3 |
0.2 |
0.1 |
|
|
|
1-Apr-21 |
|
|
0.2 |
0.1 |
|
|
1-May-21 |
|
|
0.1 |
0.2 |
0.1 |
0.1 |
1-Jun-21 |
|
|
0.1 |
0.3 |
0.2 |
0.1 |
1-Jul-21 |
|
|
0.2 |
|
|
0.2 |
1-Aug-21 |
|
|
0.2 |
|
|
0.2 |
1-Sep-21 |
|
|
0.2 |
|
|
0.2 |
1-Oct-21 |
|
|
0.3 |
|
|
0.3 |
Period Start Date
Defines the start date of each enrollment period.
Must be a valid date. If an invalid entry is made, a warning with the following message is shown:
No date found in '[value as specified for date]', to specify one, please use the one of the following formats '['%d-%b-%Y', '%d-%b-%Y', '%d %B %Y', '%d-%b-%Y', '%d %b %Y', '%B %Y', '%d %B %y', '%d-%b-%y', '%d %b %y', '%B %y', '%y-%b-%d', '%Y-%m-%d']' (e.g. 12-Apr-2021, 12-Apr-2021, 12 April 2021, 12-Apr-2021, 12 Apr 2021, April 2021, 12 April 21, 12-Apr-21, 12 Apr 21, April 21, 21-Apr-12, 2021-04-12)
In forecast calculations with RTSM data extract, the series of period start dates specified in 4C Supply® defines when further enrollments are forecasted to occur. If a period occurs before the extract date, then 4C Supply® will not consider the associated enrollment in the forecast calculation. If a period occurs after the extract date, then 4C Supply® will consider the associated enrollment in the forecast calculation.
Enrollment rate
Defines the number of patients forecasted to be enrolled in each cohort, site, or region per month. Enrollment rates are always interpreted as patients per site cohort/site/region per month; even if the periods are days and exact dates are specified as period start dates. To model enrollment per day, enter 30 times the intended enrollment rate per day. This will be interpreted as the enrollment rate per month, so the result will be the intended enrollment rate per day.
Blank cells before the first enrollment rate entry are interpreted as zero. Empty cells below an enrollment rate entry are interpreted to be the same value as the cell above.
To ensure enrolment does not continue past a certain date for any given cohort, site, or region, enter a row with 0 in the cell.
Example:
Enrollment table
Period Start Date |
Site Group A |
Site Group B |
---|---|---|
01-Jan-2024 |
2 |
2 |
01-Feb-2024 |
4 |
3 |
01-Mar-2024 |
2 |
1 |
01-Apr-2024 |
0 |
0 |
Enrollment table
Period Start Date |
Site Group A |
Site Group B |
---|---|---|
01-Jan-2024 |
2 |
2 |
01-Feb-2024 |
4 |
3 |
01-Mar-2024 |
2 |
1 |
01-Apr-2024 |
|
|
Explanation: Enrolment will stop on 31-Mar-2024 when the table on the left is used. Enrolment will continue indefinitely when the table on the right is used; the rate will stay the same, 2 patients per month for Site Group A, and 1 patient per month for Site Group B. Enrolment will continue until the cap has been reached when 0 values are not used to truncate the table.
In forecast calculations with RTSM data extract, the combination of cohort and site group or region specified in 4C Supply® for an enrollment period is the combination of cohort and site group or region where further enrollment is forecasted to occur in the associated period. If enrollment is forecasted to occur in a combination of cohort and site group or region that does not exist, a forecast calculation error is shown.