spmsDx {MSoutcomes}

Identification of secondary progressive multiple sclerosis

Description

Identify conversion from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive multiple sclerosis (SPMS), using the CORe definition, including Functional System Scores (FSS) of Expanded Disability Status Scale (EDSS). The identification of SPMS is based on clinical visit records, each record including entries for patient code, visit date, EDSS score, FSS, ambulation score, and days since most recent relapse. If a baseline EDSS score and corresponding FSS are not provided, these are determined as the first EDSS score and corresponding FSS recorded in the dataset, outside 30 days (the default) of a relapse. Following a relapse, the first EDSS score recorded in the dataset outside 30 days (the default) of a relapse, becomes the new baseline EDSS score. SPMS is sustained for the remainder of the follow-up, unless followed by two consecutive improvements in EDSS scores.

Usage

spmsDx(
  visits,
  minEDSS = 4,
  minFSpyr = 2,
  tRelapse = 30,
  tProgression = 3 * 30.25,
  tRegression = 9 * 30.25,
  tRelProg = 6 * 30.25
)

Arguments

visits

A data frame consisting of 22 columns: ID, dateEDSS, EDSS, FSpyr (pyramidal FSS), FScrbl (cerebellar FSS), FSbstem (brainstem FSS), FSsens (sensory FSS), FSsph (bowel bladder FSS), FSvis (visual FSS), FScereb (cerebral FSS), FSamb (ambulation score), dateBlineVisit, bEDSS (baseline EDSS), bFSpyr (baseline pyramidal FSS), bFScrbl (baseline cerebellar FSS), bFSbstem (baseline brainstem FSS), bFSsens (baseline sensory FSS), bFSsph (baseline bowel bladder FSS), bFSvis (baseline visual FSS), bFScereb (baseline cerebral FSS), bFSamb (baseline ambulation score), daysPostRelapse (days since most recent relapse).

minEDSS

Minimum EDSS score required to reach SPMS conversion.

minFSpyr

Minimum pyramidal FSS to reach SPMS conversion.

tRelapse

Minimum time in days since the most recent relapse to EDSS assessment.

tProgression

SPMS confirmation period in days.

tRegression

Confirmation period for EDSS improvement in days.

tRelProg

Confirmation period (days) for re-baselining EDSS (after a relapse led to non-confirmed increase in EDSS).

Value

A data frame.

References

Lorscheider J, et al. Brain 2016; 139 (9): 2395-2405.

Examples

data(SampleData)
output<-spmsDx(SampleData)