A Rasch analysis of the Person-Centred Climate Questionnaire \u2013 staff version

Mark Wilberforce,Anders Sköldunger,David Edvardsson

doi:10.1186/s12913-019-4803-9

Mark Wilberforce, Anders Sköldunger + Show 1 more

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https://doi.org/10.1186/s12913-019-4803-9

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Abstract

BackgroundPerson-centred care is the bedrock of modern dementia services, yet the evidence-base to support its implementation is not firmly established. Research is hindered by a need for more robust measurement instruments. The 14-item Person-Centred Climate Questionnaire - Staff version (PCQ-S) is one of the most established scales and has promising measurement properties. However, its construction under classical test theory methods leaves question marks over its rigour and the need for evaluation under more modern testing procedures.MethodsThe PCQ-S was self-completed by nurses and other care staff working across nursing homes in 35 Swedish municipalities in 2013/14. A Rasch analysis was undertaken in RUMM2030 using a partial credit model suited to the Likert-type items. Three subscales of the PCQ-S were evaluated against common thresholds for overall fit to the Rasch model; ordering of category thresholds; unidimensionality; local dependency; targeting; and Differential Item Functioning. Three subscales were evaluated separately as unidimensional models and then combined as subtests into a single measure. Due to large number of respondents (n = 4381), two random sub-samples were drawn, with a satisfactory model established in the first (‘evaluation’) and confirmed in the second (‘validation’). Final item locations and a table converting raw scores to Rasch-transformed values were created using the full sample.ResultsAll three subscales had disordered thresholds for some items, which were resolved by collapsing categories. The three subscales fit the assumptions of the Rasch model after the removal of two items, except for subscale 3, where there was evidence of local dependence between two items. By forming subtests, the 3 subscales were combined into a single Rasch model which had satisfactory fit statistics. The Rasch form of the instrument (PCQ-S-R) had an adequate but modest Person Separation Index (< 0.80) and some evidence of mistargeting due to a low number of ‘difficult-to-endorse’ items.ConclusionsThe PCQ-S-R has 12 items and can be used as a unidimensional scale with interval level properties, using the nomogram presented within this paper. The scale is reliable but has some inefficiencies due to too few high-end thresholds inhibiting discrimination amongst populations who already perceive that person-centred care is very good in their environment.

Highlights

Person-centred care is the bedrock of modern dementia services, yet the evidence-base to support its implementation is not firmly established
Person-centredness is internationally regarded as an essential design principle underpinning modern dementia care services
The most established measures, Dementia Care Mapping [18], demands intensive recording of care interactions by specially-trained observers which is beyond the resources of many services and research groups

Summary

Introduction

Person-centred care is the bedrock of modern dementia services, yet the evidence-base to support its implementation is not firmly established. Research is hindered by a need for more robust measurement instruments. Person-centredness is internationally regarded as an essential design principle underpinning modern dementia care services. The rise of person-centredness in dementia care finds support in an encouraging, if not definitive, evidencebase. Experimental designs have associated personcentred approaches with reduced behavioural symptoms ( agitation) and use of neuroleptics with care home residents [11,12,13]; with observational and qualitative studies having linked person-centredness with improved wellbeing and physical health outcomes [14], and benefits for care workers [15]. The most established measures, Dementia Care Mapping [18], demands intensive recording of care interactions by specially-trained observers which is beyond the resources of many services and research groups. The need for robust questionnairebased instruments has been highlighted [17]

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