Reliability and validity of the Northwick Park Dependency Score (NPDS) Swedish version 6.0

Developing a nursing dependency scoring tool for children's palliative care: the impact on hospice care

BACKGROUND

Occupancy is commonly used to measure bed management in hospices. However, the increasing complexity of children and young people and growing dependence on technology mean that this is no longer effective.

AIM

To develop a dependency tool that enables the hospice to safely and effectively manage the use of beds for planned short breaks (respite care), preserving capacity for children requiring symptom management and end-of-life care.

METHODS

A comprehensive literature review and existing tools were used to inform the development of the Martin House Dependency Tool Framework. Training was provided to staff and the tool was piloted before applying it across the hospice caseload.

FINDINGS

The tool has been used on 431 children (93.1% of caseload). The tool enabled consistency of assessment and more effective management of resources, due to a contemporaneous understanding of the clinical needs of those on the caseload.

CONCLUSION

The tool has enabled consistent and transparent assessment of children, improving safety, effectiveness and responsiveness, and the management of the workforce and resources.

The criterion-related validity of the Northwick Park Dependency Score as a generic nursing dependency instrument for different rehabilitation patient groups

Objective: To investigate the criterion or concurrent validity of the Northwick Park Dependency Score (NPDS) for determining nursing dependence in different rehabilitation groups, with the Barthel Index (BI) and the Care Dependency Scale (CDS).

Design: Cross-sectional study.

Setting: Centre for Rehabilitation of the University Medical Center Groningen, The Netherlands.

Subjects: Patients after stroke, spinal cord injury, multitrauma, head injury, amputation, rheumatoid arthritis, diabetes mellitus, lung diseases, tuberculosis and coronary artery disease. One hundred and fifty-four patients were included.

Measures: The Northwick Park Dependency Score (NPDS), the Barthel Index (BI) and the Care Dependency Scale (CDS).

Results: The correlation (rho) between the NPDS and the BI for all groups was -0.87; R2=0.76 ( n=154). Per patient group rho varied from -0.70 ( R2=0.49) to -0.93 ( R2=0.86). The overall correlation between the NPDS and CDS was larger than the criterion of rho=0.60 ( r=-0.74; R2=0.55) but was <0.60 in the rheumatoid arthritis and tuberculosis group. The overall correlation between BI and CDS exceeded the criterion ( r=0.75; R2=0.56).

Conclusions: The NPDS is a generic nursing dependency instrument that can be used as a valid measure across various patient groups in rehabilitation.

A Comparison between Two Instruments for Assessing Dependency in Daily Activities: Agreement of the Northwick Park Dependency Score with the Functional Independence Measure

Background. There is a need for tools to assess dependency among persons with severe impairments. Objectives. The aim was to compare the Functional Independence Measure (FIM) and the Northwick Park Dependency Score (NPDS), in a sample from in-patient rehabilitation. Material and Methods. Data from 115 persons (20 to 65 years of age) with neurological impairments was gathered. Analyses were made of sensitivity, specificity, positive predictive value, and negative predictive value. Agreement of the scales was assessed with kappa and concordance with Goodman-Kruskal's gamma. Scale structures were explored using the Rank-Transformable Pattern of Agreement (RTPA). Content validation was performed. Results. The sensitivity of the NPDS as compared to FIM varied between 0.53 (feeding) and 1.0 (mobility) and specificity between 0.64 (mobility) and 1.0 (bladder). The positive predictive value varied from 0.62 (mobility) to 1.0 (bladder), and the negative predictive value varied from 0.48 (bowel) to 1.0 (mobility). Agreement between the scales was moderate to good (four items) and excellent (three items). Concordance was good, with a gamma of -.856, an asymptotic error (ase) of .025, and P < .000. The parallel reliability between the FIM and the NPDS showed a tendency for NPDS to be more sensitive (having more categories) when dependency is high. Conclusion. FIM and NPDS complement each other. NPDS can be used as a measure for severely injured patients who are sensitive when there is a high need of nursing time.

Deriving a Barthel Index from the Northwick Park Dependency Scale and the Functional Independence Measure: are they equivalent?

OBJECTIVE

to examine the extent of agreement between Barthel Index scores derived from Northwick Park Dependency Scores (NPDS) and the Functional Independence Measure (FIM) ratings, in an inpatient setting.

DESIGN AND SETTING

previously described conversion criteria were applied in a secondary analysis of a large existing dataset, gathered in a tertiary specialist inpatient neurorehabilitation unit.

SUBJECTS

patients with neurological disabilities (N = 1347), mainly following acquired brain injury.

MAIN MEASURES

comparison of Barthel scores derived from the NPDS (rated by nursing staff) and from parallel FIM scores (rated by the therapy team).

RESULTS

very strong intraclass correlations were observed between the total scores (0.93, P<0.001); 95% limits of agreement ranged from -3.53 to 4.90. Item-by-item agreement (linear-weighted Cohen's kappa coefficients) ranged from 0.41 to 0.77, which represents 'moderate' to 'substantial' agreement. A significant bias towards lower NPDS-derived scores (median 10 (interquartile range (IQR) 6-16) compared with median 11 (IQR 7-16) for the FIM-derived score; Wilcoxon z 11.60, P<0.001) was considered most likely to reflect actual differences in patient performance observed by therapy and nursing staff.

CONCLUSIONS

this study demonstrates good overall agreement between the Barthel Index ratings derived from NPDS and FIM scores. However, scores may be affected by differential performance with nursing and therapy staff, and should not automatically be regarded as equivalent.

Can the Northwick Park Dependency Scale be translated to a Barthel Index?

OBJECTIVE

to develop and test an algorithm for conversion of the Northwick Park Dependency Scale (NPDS) to a Barthel Index.

DESIGN AND SETTING

conversion criteria were developed to derive a Barthel Index from NPDS data. The criteria were then applied in two community-based datasets of NPDS and Barthel scores, gathered from carers/patients via postal questionnaires. A retrospective exploratory analysis (dataset A) was followed by prospective confirmatory analysis (dataset B).

SUBJECTS

patients with neurological disabilities, mainly following acquired brain injury: dataset A (n = 225) and dataset B (n = 96).

MAIN MEASURES

comparison of NPDS-derived Barthel scores with parallel directly rated Barthel scores.

RESULTS

the exploratory analysis identified that one Barthel item ('Stairs') could not be derived from the NPDS items alone, and required minor adaptation of one of the five additional questions that are included to translate the NPDS into an assessment of community care needs (Northwick Park Care Needs Assessment, NPCNA). For the prospective confirmatory analysis, the NPCNA 'Stairs' question was adjusted to support full conversion. Very strong intraclass correlations were observed between the total 'direct' and 'derived' Barthel scores (0.97 (dataset A), 0.95 (dataset B), P<0.001); 95% limits of agreement ranged from -2.52 to 2.56 (dataset A) and -3.29-3.91 (dataset B). Item-by-item agreement (linear-weighted Cohen's kappa coefficients) ranged from 0.68 to 0.85 (dataset A) and 0.59-0.83 (dataset B), which represents 'substantial' to 'almost perfect' agreement.

CONCLUSIONS

this study demonstrates that a Barthel Index can be reliably derived from NPDS and NPCNA data through a conversion algorithm which has now been built into the supporting software package.

Development and initial validation of the Northwick Park Therapy Dependency Assessment

OBJECTIVES

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

DESIGN

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

SETTING

A tertiary specialist inpatient neurorehabilitation service.

PARTICIPANTS

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.

CONCLUSION

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.

Northwick Park Care Needs Assessment: adaptation for inpatient neurological rehabilitation settings

AIM

This paper is a report of a study to establish which timings and assumptions of the Northwick Park Dependency Scale and Care Needs Assessment are appropriate to the inpatient rehabilitation setting and which, if any, require adjustment.

BACKGROUND

Cost-effective provision of nursing care relies on being able to adjust staffing levels in accordance with patient dependency. The Northwick Park Dependency Scale and Care Needs Assessment enables direct assessment of nursing care needs in community settings.

METHOD

An observational study was conducted in 2004 to record the time taken to complete direct nursing care interventions in a rehabilitation ward and to compare these times with simultaneously recorded time-estimates provided by the Care Needs Assessment. A total of 1168 nursing interactions were timed for 50 care episodes.

RESULTS

There was considerable variation in the time taken for each nursing intervention, depending on overall patient dependency and the number of nurses required. Although there was good correlation between observed care times and those estimated by the Care Needs Assessment, observation confirmed that most interventions took substantially less time than the estimates. There was also a very different pattern of care in hospital compared with the community, with shorter, more frequent interactions as nurses distribute their time between different patients, and activities other than direct patient care.

CONCLUSION

The Northwick Park Care Needs Assessment tool already has widespread application in other countries and its continued use for estimating community care needs remains relevant. The tool, once fully developed, will have the potential to contribute to international rehabilitation nursing workforce planning and research.

Can the Northwick Park Care Needs Assessment be used to estimate nursing staff requirements in an inpatient rehabilitation setting?

AIM

To determine whether the Northwick Park Care Needs Assessment (NPCNA) could be used to estimate nursing staff requirements in an inpatient rehabilitation setting.

DESIGN

Retrospective analysis of NPCNA data in comparison with nursing staff provision over a six-month period from 1 April 2003 to 30 September 2003.

SETTING

A specialist neurorehabilitation unit.

METHODS

Daily care requirements for the ward were calculated at two-week intervals by summing the NPCNA care-hour estimates for all inpatients. Nursing staff hours provided were identified from the unit's duty rota and agency records for each corresponding period.

RESULTS

In total, 271 care-hour recordings were extracted from 59 patients. There was a poor relationship between the calculated total ward care-hour requirements and nursing staff hours provided (Pearson's r = 0.31, P = 0.29); but staff hours provided fell significantly short of estimated daily care requirements (mean shortfall 6.2 hours/day, SD 8.6 (95% confidence interval (CI) 0.73, 11.1), P = 0.03)). The shortfall was most obvious during peak care periods in the morning and at bedtime, which resonates with experience reported by nursing staff that they are overstretched at these times. A marked discrepancy between qualified nursing staff hours provided and NPCNA-estimated ;special nursing' care requirements highlights a failure to address important facets of the rehabilitation nursing role.

CONCLUSIONS

The NPCNA, which was designed to assess only direct care needs in a community setting, requires the further development of a new algorithm before it could be used to estimate nursing staff requirements in a rehabilitation ward setting.