diff --git a/src/data/translate_usernames_into_participants_data.R b/src/data/translate_usernames_into_participants_data.R
index 2dc638ca..727f9024 100644
--- a/src/data/translate_usernames_into_participants_data.R
+++ b/src/data/translate_usernames_into_participants_data.R
@@ -12,6 +12,12 @@ prepare_participants_file <- function() {
   device_id_container <- snakemake@params[["device_id_table"]]
   start_end_date_container <- snakemake@params[["start_end_date_table"]]
 
+  output_data_file <- snakemake@output[["participants_file"]]
+
+  platform <- "android"
+  pid_format <- "p%03d"
+  datetime_format <- "%Y-%m-%d %H:%M:%S"
+
   participant_data <- read_csv(username_list_csv_location, col_types = "c", progress = FALSE)
   usernames <- participant_data$label
 
@@ -31,7 +37,23 @@ prepare_participants_file <- function() {
   participant_data %<>%
     left_join(start_end_datetimes, by = "participant_id")
 
-  return(participant_data)
+  participant_data %<>%
+  mutate(
+    pid = sprintf(pid_format, participant_id),
+    start_date = strftime(datetime_start, format=datetime_format, tz = "UTC", usetz = FALSE), #TODO Check what timezone is expected
+    end_date = strftime(datetime_end, format=datetime_format, tz = "UTC", usetz = FALSE),
+    empatica_id = "placeholder", #TODO Provide in file?
+    device_id = map_chr(device_ids, str_c, collapse = ";"),
+    number_of_devices = map_int(device_ids, length),
+    fitbit_id = ""
+    ) %>%
+  rowwise() %>%
+  mutate(platform = str_c(replicate(number_of_devices, platform), collapse = ";")) %>%
+  ungroup() %>%
+  arrange(pid) %>%
+  select(pid, label, start_date, end_date, empatica_id, device_id, platform, fitbit_id)
+
+  write_csv(participant_data, output_data_file)
 }
 
-
+prepare_participants_file()