Table 5

Clinimetric evaluation of the Rehabilitation Complexity Scale (RCS): summary of findings according to the medical outcomes trust framework

Conceptual and measurement modelRationale for and description of the concept and the populations that the measure is intended to assess
Clinical content and design
  • RCS is a five-item ordinal scale, scored on a range of 0 to 15

  • Designed to provide a simple measure of the complexity of rehabilitation needs and/or interventions, which is timely to apply and takes account of basic care, specialist nursing, therapy and medical interventions

  • In this evaluation, it was tested in the context of ‘interventions provided’

DimensionalityExploratory and confirmatory factor analyses showed strong evidence that the RCS has two distinct dimensions (‘Nursing/medical care’ and ‘Therapy’)
ReliabilityDegree to which the instrument is free from random error
Internal consistencyCronbach α 0.76 and item-total correlations (0.51 to 0.78) showed moderate internal consistency
ReproducibilityTest–retest repeatability after 2 h using the ward-round as a distracter task: quadratic-weighted κ values were 0.93, 0.96 and 0.94 for the care, nursing and medical items, respectively, constituting excellent agreement; repeatability for therapy (TD and TI) items was not tested in this evaluation
ValidityDegree to which the instrument measures what it purports to measure
ContentRCS items C, N, T and M are the principal ‘causes’ of case complexity, which (together with length of stay) ultimately determine the cost of a rehabilitation episode
Criterion-relatedNot testable—no accepted gold standard currently exists
ConcurrentConvergent and discriminant validity tested against Northwick Park Nursing and Therapy Dependency Scores: the RCS Care/Nursing scores correlated strongly with other measures of nursing dependency (r 0.70 to 0.80), while the T scores* correlated weakly (0.26); conversely, the T scores correlated with the therapy dependency (0.72)
ResponsivenessAbility to detect change over time where real changes occur
Change: admission to dischargeRCS scores changed significantly over the course of a 3–4-month stay, but the items changed in different directions: C, N and M interventions (C+N+M) reduced (Wilcoxon z −9.0, p<0.001), while therapy interventions (TD+TI) increased (Wilcoxon z −4.6, p<0.001)
InterpretabilityDegree to which easily understood meaning can be assigned to the quantitative scores
Clinical meaningRCS is recommended to be reported by item: eg, RCS 8=C2 N1 T4 M1, as the level descriptors provide a clinical description of needs/interventions that is useful for treatment planning; this evaluation also supports summation into two subscales: nursing medical care (C+N+M) and therapy (TD+TI)
BurdenTime, effort or other demands of administering the instrument
Time to administer
  • RCS is designed to be intuitive and requires minimal training

  • In this study, it took less than 1–2 min to administer by a team who was familiar with the scoring manual and used the score regularly in routine practice

Alternative modes of administrationNone currently available
Cultural and language adaptationsNone currently available
  • * RCS T score=TD+TI.

  • C, care; M, medical; N, nursing; T, therapy; TD, therapy disciplines; TI, therapy intensity.