R Filter by sequence of events - r

Question

I have an event log data. For reproducible example, let's use the data from eventdataR
eventdataR::patients
## look at patient 1 sequence
eventdataR::patients %>% dplyr::filter(patient == '1')
# A tibble: 12 x 7
handling patient employee handling_id registration_ty~ time .order
<fct> <chr> <fct> <chr> <fct> <dttm> <int>
1 Registration 1 r1 1 start 2017-01-02 11:41:53 1
2 Triage and A~ 1 r2 501 start 2017-01-02 12:40:20 2
3 Blood test 1 r3 1001 start 2017-01-05 08:59:04 3
4 MRI SCAN 1 r4 1238 start 2017-01-05 21:37:12 4
5 Discuss Resu~ 1 r6 1735 start 2017-01-07 07:57:49 5
6 Check-out 1 r7 2230 start 2017-01-09 17:09:43 6
7 Registration 1 r1 1 complete 2017-01-02 12:40:20 7
8 Triage and A~ 1 r2 501 complete 2017-01-02 22:32:25 8
9 Blood test 1 r3 1001 complete 2017-01-05 14:34:27 9
10 MRI SCAN 1 r4 1238 complete 2017-01-06 01:54:23 10
11 Discuss Resu~ 1 r6 1735 complete 2017-01-07 10:18:08 11
12 Check-out 1 r7 2230 complete 2017-01-09 19:45:45 12
In the above example, we can see the sequence of handling for patient 1 over a period of time. We can imagine that different patients would have different sequences or went through different number of sequences.
Now let's say I'm interested in a specific sequence and want to know which patients had gone through this specific sequence. How can I filter this dataset by this specific sequence so that I can get to know who these patients are?
The filter_activity_presence from edeaR library can help me with identifying the unique sequences and its frequency
patients %>% traces
# A tibble: 7 x 3
trace absolute_frequen~ relative_frequen~
<chr> <int> <dbl>
1 Registration,Triage and Assessment,X-Ray,Discuss R~ 258 0.516
2 Registration,Triage and Assessment,Blood test,MRI ~ 234 0.468
3 Registration,Triage and Assessment,Blood test,MRI ~ 2 0.004
4 Registration,Triage and Assessment,X-Ray 2 0.004
5 Registration,Triage and Assessment 2 0.004
6 Registration,Triage and Assessment,X-Ray,Discuss R~ 1 0.002
7 Registration,Triage and Assessment,Blood test 1 0.002
Let's say I'm interested in sequence from row 5, that is patients who had exclusively this sequence Registration -> Triage -> Assessment, there are 2 patients who had this sequence.
It seems the library that doesn't provide ready made function to extract this. At least from this doc page, https://www.bupar.net/subsetting.html#trace_length, it's not available.
Basically, given an exhaustive list of sequence, return all the patients who had gone through exactly this sequence.
In fact, if I can rebuild the trace and map it back to the original dataset, that should allow for a simple dplyr::filter. But this may not be ideal as well in the case if I'm interested in open ended sequence, for example, find all patients who started with Registration -> Triage and can be followed by any sequence.
Here's my long-winded attempt
# get trace for each patient
patient_trace <- as_tibble(patients) %>% group_by(patient) %>% dplyr::filter(registration_type == 'complete') %>%
summarise(trace = paste(handling, collapse = ","), n = n())
# identify the sequence trace of interest
trace_summary <- patients %>% traces
# here we want to see patients who had the sequence from row 5
res <- patients %>%
dplyr::filter(patient %in% c(patient_trace %>% dplyr::filter(trace %in% trace_summary$trace[5]) %>% .$patient)) %>%
dplyr::filter(registration_type == 'complete') %>%
arrange(patient, time)
# A tibble: 4 x 7
handling patient employee handling_id registration_ty~ time .order
<fct> <chr> <fct> <chr> <fct> <dttm> <int>
1 Registration 499 r1 499 complete 2018-05-01 22:57:38 1
2 Triage and As~ 499 r2 999 complete 2018-05-04 23:53:27 3
3 Registration 500 r1 500 complete 2018-05-02 01:28:23 2
4 Triage and As~ 500 r2 1000 complete 2018-05-05 07:16:02 4

Answer 1

You can filter them with dplyr :
library(dplyr)
req_sequence <- c('Registration', 'Triage and Assessment')
eventdataR::patients %>%
group_by(patient) %>%
filter(all(handling == req_sequence)) %>%
filter(registration_type == 'complete') %>%
ungroup
# handling patient employee handling_id registration_type time .order
# <fct> <chr> <fct> <chr> <fct> <dttm> <int>
#1 Registration 499 r1 499 complete 2018-05-01 22:57:38 3220
#2 Registration 500 r1 500 complete 2018-05-02 01:28:23 3221
#3 Triage and Assessment 499 r2 999 complete 2018-05-04 23:53:27 3720
#4 Triage and Assessment 500 r2 1000 complete 2018-05-05 07:16:02 3721
For this case to be sure of the output and to avoid any recycling effect we can filter registration_type == 'complete' first and also add another check of length(req_sequence) equal to number of rows for the patient id.
eventdataR::patients %>%
filter(registration_type == 'complete') %>%
group_by(patient) %>%
filter(length(req_sequence) == n() && all(handling == req_sequence)) %>%
ungroup