Development and initial validation of the Northwick Park Therapy Dependency Assessment.
OBJECTIVE
To describe the development and initial validation of the Northwick Park Therapy Dependency Assessment (NPTDA) as a measure of therapy interventions in neurorehabilitation.


METHODS
An iterative development process, followed by comparison with systemic prospective activity analysis, and parallel application of prospective and retrospective scores.


METHODS
A tertiary specialist inpatient neurorehabilitation service.


METHODS
A total of 37 patients (M:F 21:16, mean age 41.8 (SD 14.7) years) with complex neurological disability in two consecutive cross-sectional cohorts.


METHODS
The NPTDA was developed and refined over 18 months, together with an algorithm that converts ordinal scores to estimated therapy hours/week. NPTDA-estimated hours were compared with 'actual' therapy hours/week, identified from activity analysis. In a subsequent cohort analysis, prospectively rated NPTDA scores (reflecting intended levels of intervention) were compared with retrospective NPTDA scores (actual interventions).


RESULTS
NPTDA-estimated therapy hours/week were strongly correlated with those identified from activity analysis, for total scores (Spearman rho 0.77, P<0.0001), and also for all five subdomains for direct (hands-on) intervention (rho 0.70-0.93, P<0.0001). The initial test algorithm overestimated therapy hours (Wilcoxon z =3.9, P<0.001). After adjustment, reanalysis using a revised algorithm showed this bias to be removed (Wilcoxon z =1.4 P =0.15). Prospective and retrospectively applied total NPTDA scores were strongly correlated (rho 0.61, P<0.0001). Although intended levels of intervention were higher than those actually delivered (Wilcoxon z =3.30, P<0.001), the differences corresponded to real deviations from intended practice.


CONCLUSIONS
In this initial evaluation, after revision of the algorithm, the NPTDA provided acceptable estimate of therapy interventions. Further evaluation is now required in other populations and settings.
King's College London, School of Medicine, Department of Palliative Care, Policy and Rehabilitation and Regional Rehabilitation Unit, Northwick Park Hospital, Harrow, UK. Lynne.turner-stokes@dial.pipex.com
Lynne
L
Turner-Stokes
Asa
A
Shaw
Janet
J
Law
Hilary
H
Rose
D000328:Adult; D000465:Algorithms; D004185:Disability Evaluation; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000534:rehabilitation*; D015588:Observer Variation; D017063:Outcome Assessment, Health Care; D016526:Workload