Predictors of substantial improvement in physical function six months after lumbar surgery: is early post-operative walking important? A prospective cohort study

Table 4 Summary of Included and Excluded Data

	Excluded (N)	Included (N)
Invited to participate:		262
Declined	17
Excluded
Unable to provide informed consent	4
Co-existing condition limiting walking	6
Withdrew consent	2
Completed pre-operative OM’s and activity monitoring:		233^a
Lost/faulty monitor	27
Incomplete monitoring period	16
Incomplete outcome measures	19
Data sets available for multivariable analysis:		171
Included in multivariable analysis^b:
ODQ	14	157
SF-36 (PCS)	17	154
Back pain	n/a	n/a
Leg pain	18	196^c

OM’s Outcome measures, ODQ Oswestry Disability Questionnaire, SF-36 (PCS) Short Form 36 Physical Component Summary
^aTotal number included in sensitivity analysis using multiple imputation to estimate missing data; ^bRemaining exclusions from individual regression analyses were due to incomplete individual outcome measures or missing independent variable data; ^cWalking time was not significantly correlated with change in leg pain, the 43 participants with missing activity monitor data included in the multivariable analysis

ISSN: 1471-2474