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Effects of community based nurses specialising in Parkinson's disease on health outcome and costs: randomised controlled trial |
Jarman B, Hurwitz B, Cook A, Bajekal M, Lee A |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The use of community-based nurses for the management of patients with Parkinson's disease (PD). Nurses completed a course on special needs of people with PD and their carers. Their position in the community was advisory to the general practitioner (GP), rather than clinically autonomous. The nurses had a leased car and a mobile phone, and kept a diary of their daily work.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients taking one or more antiparkinsonian drugs. Patients younger than 17 years of age, or those with severe mental illness or cognitive impairment, were excluded.
Setting The setting was primary care. The economic study was conducted in the UK.
Dates to which data relate The effectiveness and resource use data were collected from 1996 to December 1999. The price year was 1996.
Source of effectiveness data The effectiveness evidence was derived from a single study.
Link between effectiveness and cost data The costing was conducted prospectively on the same sample of patients as that used in the effectiveness study.
Study sample Power calculations were conducted in the preliminary phase of the study. These suggested that, with an expected dropout rate of 15%, an initial sample of 1,600 patients would be required to detect a 10% change in a categorical outcome having an initial prevalence of 50%, with 80% power at a 5% significance level. From the 57 English health authorities that did not develop community-based services of nurse specialists in PD across UK, nine health authorities were randomly selected and eligible patients were identified. Recruitment was difficult in one area. Therefore, the second randomly selected health authority participated into the study.
Of the 3,124 eligible patients, 1,265 did not agree to participate, while 1,859 were included in the study sample. There were 1,041 patients in the intervention group and 818 in the control group. However, 13 (intervention group) and 10 (control group) patients died before the start of the programme. The final sample therefore comprised 1,028 patients in the intervention group and 808 patients in the control group. The proportion of males was 57.2% (intervention group) versus 56.4% (control group). In terms of age class, 34.4% of the patients in the intervention group were aged younger than 70 years, 34.9% were aged 70 to 77 years, and 30.6% were older than 77 years. The corresponding proportions in the control group were 31.7% (<70 years), 35.9% (70 to 77 years) and 32.4% (>70 years), respectively.
Study design This was a prospective, randomised controlled trial that was conducted in several practices across the UK. An independent survey organisation carried out the blocked randomisation. The patients were randomised within the practice and, where numbers permitted, were stratified within each practice by age (<70, 70 - 77, >70), gender, and duration of disease (<5, 5 - 9, >9 years). The length of follow-up was 2 years. The outcomes were assessed at baseline, and 1 and 2 years. Follow-up of mortality continued for 4 years. After 2 years, 163 patients in the intervention group and 116 in the control group were lost to follow-up. No blinding was conducted.
Analysis of effectiveness The analysis of effectiveness was restricted to the patients whose follow-up data were available. Therefore, the analysis of the clinical study appears to have been conducted on the basis of treatment completers only. The primary outcome measures were overall health status, other indicators of health states and ability to perform usual activities, mortality, use of antiparkinsonian drugs, referrals, and nurse activity.
Overall health status was evaluated using a questionnaire assessing the self-perceived global health question over the 2-year timeframe. There were five possible responses ranging from 0 (best) to 8 (worst).
Other indicators of health states and ability to perform usual activities included the Euroqol (higher scores represent better values), the Parkinson Disease Questionnaire (PDQ)-39, the dot in square test, the Colombian rating scale, and the number of adverse effects (e.g. fractures). The PDQ-30 was a disease-specific measure ranging from 0 (good) to 100 (bad). The dot in square test assessed the patient's ability to put dots in a grid of 90 squares within 30 seconds. The Colombian rating scale was used to test the patient's ability to rise from a chair with a hard seat to allow "push-off".
The study groups were comparable at baseline in terms of their age, gender, accommodation, social class, disease duration, disease severity and drug use. Comparative data were not available for participants versus non-participants, but the authors stated that the study sample was generally representative of the population of England and Wales with PD. The exception was the under-representation of patients aged 85 years or older.
Effectiveness results In the whole group of patients, global health deteriorated and the average self-perceived global health score was 4.89 at the end of the follow-up period. Similar worsening, which was consistent with the progression of disease, was observed using the other indicators of health states and functional dimensions.
At the end of the follow-up period, the study groups were comparable in terms of the Colombian rating scale, the number of bone fractures, the dot in square test, mortality, the Euroqol and the PDQ-39. However, the score for global health was 4.79 (+/- 1.50) in the intervention group and 5.02 (+/- 1.38) in the control group. The difference of -0.23 (95% confidence interval, CI: -0.40 - -0.06) was statistically significant, (p=0.008).
In relation to changes in medical treatments, the median daily dose of levodopa increased from 300 to 400 mg with no significant differences between the groups. In addition, the proportion of patients taking a controlled-release form of levodopa increased from a third of each treatment group at baseline to 52.5% of the intervention group and 45.3% of the control group, (p=0.016). Similarly, there was a statistically significant tendency for patients in the intervention group to discontinue taking selegiline. After 2 years, 71.8% of the intervention patients versus 54.8% of the control patients had discontinued selegiline use, (p<0.001).
No statistically significant differences were observed in the proportions of patients taking anticholinergics, dopamine antagonists, or apomorphine, or in the number of different types of drugs prescribed.
Referrals were comparable between the groups.
Nurses assessed an average of 13.7 patients per week, 75% at home, 14% at general practices, and 11% in hospital consultant clinics. Each patient received on average 8 assessments per year. Every week, nurses also spent 6 hours on administration, letter writing and telephoning patients, and 8.4 hours on travelling.
Clinical conclusions The effectiveness analysis showed that, compared with standard care delivered by GPs, the implementation of a community-based nurse service for the management of patients with PD had little impact on the clinical progression of disease. A statistically significant improvement was observed only in global health, but this was not corroborated when other measures of quality of life were used.
Measure of benefits used in the economic analysis The health outcomes were left disaggregated and no summary benefit measure was used in the economic analysis. In effect, a cost-consequences analysis was conducted.
Direct costs Discounting could have been relevant as the costs were assessed for 1 year before the intervention and 2 years post-intervention. However, no discounting was applied. The unit costs and the quantities of resources used were not presented separately. The health services included in the economic evaluation were nurse specialist, institutional expenses, respite care, hospital services, primary health care, therapy, drugs (excluding apomorphine) and home help. The costs incurred by the carers were not considered. The cost/resource boundary of the local health authority was used. Resource use was estimated using actual data collected alongside the clinical trial in which, at study entry, the patients self-reported the expenses incurred in the year preceding the intervention. The costs were estimated from the Personal Social Services Research Unit and the Monthly Index of Medical Specialties. The price year was 1996.
Statistical analysis of costs An unpaired t-test was used to test the statistical significance of differences in the estimated costs. As the data were highly skewed, 2,000 bootstrapped samples were used to check all the results. The results were presented as average values for differences, with corresponding CIs.
Indirect Costs The indirect costs were not considered.
Sensitivity analysis Sensitivity analyses were not conducted.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results In the intervention group, the costs increased from 4,050 (maximum 55,400) in the year preceding the study to 5,860 (maximum 39,100) in year 2. The mean individual increase was 2,540 (maximum 34,600).
Similarly, in the control group, the costs increased from 3,480 (maximum 35,000) in the year preceding the study to 5,630 (maximum 33,100) in year 2. The mean individual increase was 2,800 (maximum 31,600).
The difference in the mean individual increase between the intervention and control groups was not statistically significant, (difference -0.26, 95% CI: -0.98 - 0.45; p=0.47).
Synthesis of costs and benefits A synthesis of the costs and benefits was not relevant since a cost-consequences analysis was conducted.
Authors' conclusions Although the community-based nurses specialising in the care of patients with Parkinson's disease (PD) had little effect on the clinical conditions of patients, they did bring about an improvement in the patients' sense of well-being, without increasing the overall costs from the perspective of the local health authority.
CRD COMMENTARY - Selection of comparators The choice of the comparator was appropriate as GP care represented the standard approach for the management of patients with PD. You should decide whether this is a valid comparator in your own setting.
Validity of estimate of measure of effectiveness The effectiveness evidence came from a clinical trial, which was appropriate for the study question. The internal validity of the analysis was enhanced by several factors. For example, the stratified and blocked randomisation, the baseline comparability of the study groups, and the use of power calculations to determine the adequate sample size. Also, the appropriate length of follow-up, the use of validated measures to assess outcome measures, and the multi-centre design. The impact of selection bias and confounding factors was reduced by the strong design. Blinding was not feasible because of the type of interventions being evaluated. The study sample was representative of the study population. However, the analysis of effectiveness was not conducted on an intention to treat basis. The authors also noted that some non-parkinsonian patients could have been included in the sample because of mistakes in case assessment. However, bias such as this was likely to have had a similar effect on both groups. Further, the nurses involved in the study were unlikely to be representative of experienced nurse specialists because they were on a professional learning curve.
Validity of estimate of measure of benefit No summary benefit measure was used in the analysis because a cost-consequences analysis was conducted.
Validity of estimate of costs The authors explicitly stated the perspective adopted in the study. As such, it appears that all the relevant categories of costs have been considered. A detailed breakdown of the cost items was provided, but no information on resource use or unit costs was given. This means that it would be difficult to replicate the study. The cost estimates were specific to the UK settings and caution should be exercised when extrapolating the results of the cost analysis to other contexts. The source of the data was reported. Appropriate statistical tests were conducted to deal with the skewed distribution of the costs. However, carer costs, which were not considered on the grounds that they were irrelevant, are likely to represent a substantial component of the overall societal costs of the disease.
Other issues The authors compared their findings with those from other studies that had reported similar results. However, the issue of the generalisability of the study results to other settings was not addressed, and sensitivity analyses were not conducted. This reduced the external validity of the analysis. The study involved the whole population of patients with PD and this was reflected in the authors' conclusions.
Implications of the study The study results suggested that the provision of community-based nurse specialists in PD helps to preserve the patients' sense of well-being, without slowing clinical progression of the condition or increasing the costs. However, caution is required when interpreting the results of the analysis, because the improvement in well-being was close to the non significant threshold and was not confirmed when other measures were used.
Source of funding Funded by the Paul Hamlyn Foundation, the Parkinson's Disease Society, and Brittania Pharmaceuticals.
Bibliographic details Jarman B, Hurwitz B, Cook A, Bajekal M, Lee A. Effects of community based nurses specialising in Parkinson's disease on health outcome and costs: randomised controlled trial. BMJ 2002; 324: 1072-1075 Other publications of related interest Jahanshahi M, Brown C, Whitehouse C, et al. Contact with a nurse practitioner: a short-term evaluation study in Parkinson's disease and dystonia. Behavioural Neurology 1994;7:189-96.
Indexing Status Subject indexing assigned by NLM MeSH Adult; Aged; Community Health Nursing /economics /organization & England; Family Practice /economics /organization & Female; Follow-Up Studies; Health Care Costs; Health Status Indicators; Humans; Male; Middle Aged; Nurse's Role; Odds Ratio; Parkinson Disease /economics /nursing; Survival Rate; Treatment Outcome; administration; administration AccessionNumber 22002008120 Date bibliographic record published 31/12/2004 Date abstract record published 31/12/2004 |
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