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Economic analysis of two structured treatment and teaching programs on asthma |
Neri M, Migliori G B, Spanevello A, Berra D, Nicolin E, Landoni C V, Ballardini L, Sommaruga M, Zanon P |
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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 Using a complete (CP) versus reduced (RP) educational programme on asthma to reduce the asthma-induced incidents in asthma patients. The CP group received six lessons based on an educational booklet and educational videotapes, while the RP group had only a self-reading of the same educational booklet. The patients in both programmes received peak-flow monitoring and treatment according to international guidelines, and follow-ups.
Economic study type Cost-effectiveness analysis.
Setting Hospital. The economic study was carried out in Italy.
Dates to which data relate Effectiveness and resource use data related to the two educational programmes were gathered between October 1993 and June 1994. The corresponding data for the "no educational programme" option were based on the year before the study initiation. The fiscal year was 1994.
Source of effectiveness data Effectiveness data were derived from a single study.
Link between effectiveness and cost data Costing was performed on the same patient sample as that used in the effectiveness analysis. The costing was undertaken retrospectively for the year before enrolment and prospectively for the year after enrolment (the data were collected by patients based on a custom-designed daily diary).
Study sample Power calculations were used to determine the sample size based on the results of an earlier pilot study including a biologic and an economic variable (with alpha equal to 0.05 and power of 0.85). The study sample consisted of 80 patients equally assigned to the CP group (n=40) with an average (SD) age of 47.1 (13.9) years or the RP group (n=40) with an average (SD) age of 44.3 (7.9) years.
Study design With respect to the two study programmes compared in the post-enrolment period, the study may be regarded as a randomised controlled trial. However, in the case of comparing the post-enrolment with the pre-enrolment period, it may be regarded as a before-and-after study, carried out in 2 centres. The duration of the follow-up was 1 year. The dropout rate was 18.8% (7 dropouts in the CP group and 8 in the RP group).
Analysis of effectiveness The principle (intention to treat or treatment completers only) used in the analysis of effectiveness was not explicitly specified. The health outcome measures were number of asthma attacks, urgent medical examinations, admission days, and working days lost. The study groups were shown to be comparable in terms of potential confounding variables.
Effectiveness results The mean number of asthma attacks for the year before enrolment was 8.40 in the CP group versus 7.84 in the RP group. The corresponding figures for the mean number of urgent medical examinations was 1.66 versus 1.87, for admission days was 6.59 versus 7.24 and for working days lost was 9.4 versus 10.4. The differences between the two groups for the pre-enrolment period were not statistically significant. The mean number of asthma attacks for the year after enrolment was 4.72 in the CP group versus 7.91 in the RP group. The corresponding figures for the mean number of urgent medical examinations was 0.72 versus 2.18, for admission days was 0.12 versus 0.12 and for working days lost was 2.1 versus 5.1. The differences between the two groups for the after-enrolment period were not statistically significant except for the number of urgent medical examination, (p<0.05). The differences between the pre- and post-enrolment outcomes for the PC group were statistically significant except for the number of working days lost. The corresponding differences for the RP group were not statistically significant except for the number of admission days.
Clinical conclusions "Since both programs were similarly designed as to diagnosis, treatment, follow-up of patients, and produced similar outcomes", the authors "agree that the key features of an asthma program should be proper treatment and regular supervision of asthmatics."
Measure of benefits used in the economic analysis The benefit measures were the number of episodes prevented for outcome variables (number of asthma attacks, urgent medical examinations, admission days, and working days lost).
Direct costs Costs were not discounted because of the one-year follow-up of the study. Quantities (specifically time consumption) were reported separately from the costs. Cost components were reported separately. The cost analysis covered the costs of medical examination, spirometry, PEF monitoring, lessons, booklet; and follow-up phase. The perspective adopted in the cost analysis was that of a health programme policy maker (HPP) and society as a whole (SaW). The sources of cost data were national statistics and the Italian Ministry of Health. 1994 price data were used. The cost of additional diagnostic procedures was excluded from the analysis.
Statistical analysis of costs Student's t test was used to compare the groups in terms of costs.
Indirect Costs Costs were not discounted because of the one-year follow-up of the study. Quantities were reported separately from the costs. Cost components were reported separately. The cost analysis covered the costs of loss of productivity due to absence from work. The perspective adopted in the cost analysis was that of a working patient. The sources of cost data were national statistics. 1994 price data were used.
Currency Italian lira (L). A conversion to US dollars was carried out based on the January 1995 exchange rate of $1.00= L 1,623.9.
Sensitivity analysis One-way sensitivity analysis was performed on the key variables using upper and lower values of the confidence interval.
Estimated benefits used in the economic analysis 3.68 asthma attacks were prevented in the CP group compared to -0.07 in the RP group. The values (CP versus RP) for the urgent medical examinations were 0.94 versus -0.32, for admission days were 6.47 versus 7.12, and for working days lost were 7.3 versus 5.3.
Cost results The CP group had an average programme cost of $713.2 versus $669.8 for the RP group. The net savings for the CP group compared to the before-enrolment period was $1,181.5 from the perspective of society and S636.3 from that of health policy makers. The corresponding values for the RP group were $1,028 and $632.
Synthesis of costs and benefits The cost per unit of effect for outcome variables and incremental cost-effectiveness ratio (CP relative to RP) were calculated as the measures of synthesis of costs and benefits. The cost per unit of effect for the CP group in terms of asthma attacks, urgent medical examinations, admission days, and working days lost was $193.8, $758.7, $110.2, and $97.7, respectively. The corresponding values for the RP group were $669.84, $669.84, $94.01, and $125.4. The incremental cost-effectiveness ratio in terms of asthma attacks, urgent medical examinations, and working days lost were $11.6, $34.4, and $21.7, respectively. The sensitivity analysis demonstrated that the results were not consistent over a broad range of alterations in the values of key variables.
Authors' conclusions CP gave slightly better results and was slightly more cost-effective than RP in improving patients' welfare. It cannot be excluded that the retrospective analysis used to determine baseline costs might have inflated differences for both groups. Sensitivity analysis was slightly in favour of RP when the outcome variables were tested at their upper and lower 95% confidence interval.
CRD COMMENTARY - Selection of comparators The reason for the choice of the comparator is clear. Treatment and teaching programmes for asthma are generally known to result in benefits, which outweigh costs. You, as a use of this database, should consider whether this is a widely used practice in your own setting.
Validity of estimate of measure of benefit The estimates of benefits are likely to be internally valid given the sample size and the randomised design of the study comparing the CP with the RP group. The before-and-after design of the within-group study has the potential for recollection bias, which has been addressed by counterchecking with the medical records. The principle of the analysis of effectiveness (intention to treat or treatment completers only) was not specified.
Validity of estimate of costs Quantities (specifically time consumption) were reported separately from the costs. Adequate details of the methods of cost estimation were given. Cost results may not be generalisable to other settings or countries.
Other issues The authors reported cost-benefit ratios, but as health outcomes were not measured in monetary terms, it was incorrectly considered that a cost-benefit analysis had been carried out. Further information about the sensitivity analysis would have been useful. Adequate comparisons were made with other studies in the literature.
Implications of the study Further studies exploring the cost-effectiveness of educational programmes for asthma patients are needed where their effect on the patents' quality of life would also be considered.
Source of funding Partially funded by the Fund for Current Research, Italian Ministry of Health, 1994.
Bibliographic details Neri M, Migliori G B, Spanevello A, Berra D, Nicolin E, Landoni C V, Ballardini L, Sommaruga M, Zanon P. Economic analysis of two structured treatment and teaching programs on asthma. Allergy 1996; 51(5): 313-319 Indexing Status Subject indexing assigned by NLM MeSH Adult; Asthma /economics /prevention & Cost-Benefit Analysis; Data Collection; Female; Humans; Male; Middle Aged; Patient Education as Topic; control /therapy AccessionNumber 21996000794 Date bibliographic record published 29/02/2000 Date abstract record published 29/02/2000 |
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