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Follow-up in colorectal cancer: cost-effectiveness analysis of established and novel concepts |
Staib L, Link K H, Beger H G |
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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 health intervention examined in the study was an intensive long-term follow-up programme in patients with colorectal cancer. The 10-year programme consisted of three visits in each of the first two years, two visits with technical examination in each of years 3, 4 and 5, and thereafter annual visits (years 6-10) without technical examinations. Visits included patient history and physical examination, such as digital rectal examination, faecal occult blood test (FOBT), complete blood profile (blood count, transaminases, lactic dehydrogenase, LDH), and carcino-embryonic antigen (CEA) test. Technical tests included, depending on tumour entity, abdominal ultrasound, chest radiography (CXR), colonoscopy, CT of the pelvis, and rigid procto-rectoscopy. The follow-up programmes stopped in cases of cancer recurrence, severe other diseases, patient death, or on patients demand.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients who underwent curative colorectal cancer resection.
Setting The setting of the study was a university hospital. The study was conducted at the Department of General and Visceral Surgery, University of Ulm, Germany.
Dates to which data relate Data on effectiveness and resource use were gathered from 1978 to 1989 for the main intervention and from 1983 to 1994 for the comparators. No price year was used.
Source of effectiveness data The effectiveness evidence was derived from a single study and a review of the literature.
Link between effectiveness and cost data The costing was undertaken prospectively on the same patient sample as that used in the effectiveness analysis for the intervention.
Study sample Power calculations were not carried out. A total sample of 1,054 patients (aged over 70 years) who underwent curative colorectal cancer resection at the authors' institution from January 1978 to December 1989 participated into the study. Although not specifically reported, it appears that no subject was excluded from the initial sample.
Study design The study was based on a cohort of patients undergoing follow-up procedures at the authors' institution (Department of General and Visceral Surgery at the University of Ulm). Patients were followed for 10 years and the median observation period after treatment for cancer recurrence was 24 months (range: 7 - 96 months).
Analysis of effectiveness It appears that all patients included in the study were accounted for in the effectiveness analysis. The primary health outcome was "the number of patients with asymptomatic tumour recurrence, solely detected by the follow-up programme and who survived after surgical treatment for recurrence, divided by all patients in the follow-up programme". No analysis of the comparability of groups was conducted, since a single cohort of patients was used in the effectiveness analysis.
Effectiveness results The number of patients experiencing a relapse was 350 (33%). Of these, 56 patients (16%) were resectable, and 21 (6%) were successfully cured. As a result, 21 patients out of the 1,054 included in the study (2%) had a direct benefit from the follow-up programme.
Clinical conclusions The effectiveness of the 10-year follow-up programme was relatively low, since only 2% of the patients included in the study were successfully cured.
Outcomes assessed in the review The outcomes assessed in the review were tumour recurrence rate, rates of curative surgery, and 5-year overall survival.
Study designs and other criteria for inclusion in the review The primary studies were mainly prospective, randomised-controlled trials. Several non-randomised, prospective studies were also included in the review, but results were not reported.
Sources searched to identify primary studies The MEDLINE database was searched from 1980 to 2000 using the key-words 'follow-up', 'colorectal', 'costs', and 'randomized'.
Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included Overall, 61 studies were found from the literature review, with 5 randomised and 16 non-randomised primary studies being used in the effectiveness analysis.
Methods of combining primary studies Primary studies were not combined.
Investigation of differences between primary studies The authors stated that all studies were two armed and none were risk armed. Three studies did not differentiate between colon and rectal cancer. None of the studies mentioned the treatments used after recurrence of tumour for patients who were not resectable.
Results of the review Tumour recurrence rates ranged from 19% to 42% while the rates of curative surgery varied between 4.8% and 65%. The 5-year overall survival ranged from 54% to 75%. However, only one study found a statistically significant improvement in survival in patients intensively followed in comparison with patients who underwent the standard follow-up. In the remaining primary studies, the intensive follow-up programme was not more effective than the standard programme in terms of survival and recurrence rates.
Measure of benefits used in the economic analysis The benefit measure used in the economic analysis was the percentage of patients cured and was derived directly from the effectiveness analysis.
Direct costs Costing was only given for the intervention. Discounting was not conducted, although it would have been relevant, given the long time horizon of the study. Unit costs were reported, but quantities of resources were not. The cost/quantity boundary was not clearly reported. The cost items included in the analysis were personnel, infrastructure, and test costs. Transportation costs, work-dispensation costs, and costs of diagnostic tests if recurrence was suspected were not included. The estimation of costs and quantities of resources was based on both actual data (from the authors' institution) and a review of published studies. Costs were derived from reimbursement rates of insurance companies. Resources were measured from 1978 to 1989. No price year was reported.
Statistical analysis of costs No statistical analysis of costs was conducted.
Indirect Costs Indirect costs were not included.
Currency Euros (DM 1.00 = Euro 0.45).
Sensitivity analysis No sensitivity analyses were carried out.
Estimated benefits used in the economic analysis The number of cured recurrence patients by the intervention was 21, equal to 2% of the total sample (follow up: 7 - 96 months). That for the other methods found in the literature review was 54 - 75% (5 year survival).
The difference in overall 5-year survival between the two interventions (standard (n=3) or no follow-up (n = 2) versus intensive follow-up groups) ranged from 2 to 14.8% in favour of intensive/technical follow-up.
Cost results Unit costs amounted to:
Euro 8 for physical examination;
Euro 10 for CEA;
Euro 19 for blood tests;
Euro 7 for FOBT;
Euro 36 for abdominal ultrasound;
Euro 37 for chest-radiography;
Euro 198 for colonoscopy;
Euro 33 for rectoscopy (only rectum); and
Euro 411 for CT-pelvis (only rectum).
The total costs for a 10-year follow-up programme were Euro 2,220 for a colon-cancer patient and Euro 4,851 for a rectal-cancer patient.
Costs in the 5 RCTs reviewed varied between Euro 616 for minimal and Euro 5,049 for intensive follow-up.
Synthesis of costs and benefits Costs and benefits were combined by calculating the cost-effectiveness ratio. Since, for the total sample of 1,054 patients, the 10-year follow-up programme cost Euro 6.3 million and only 21 patients were cured, the cost for the 21 cured patients was Euro 126,000 and the cost-effectiveness ratio was 50:1.
Authors' conclusions The authors concluded that the follow-up programme implemented at their institution was cost-intensive and produced only a small benefit, since 98% of followed patients had no direct benefit from the programme because either they did not develop tumour recurrence or their recurrence was not surgically curable. It appears that follow-up programmes that focussed on high-risk patients could be more cost-effective.
CRD COMMENTARY - Selection of comparators The selection of the comparators was not clear, since an explicit comparison group was not considered and the follow-up programmes reviewed from the literature were slightly different in terms of number of routine visits and tests conducted. In fact, cost-effectiveness was calculated incorrectly in that it was not incremental, i.e., no comparison was made with the effectiveness or cost of an alternative, i.e. a comparator. You, as a user of this database, should assess the type of follow-up programme implemented in your own setting.
Validity of estimate of measure of effectiveness The analysis of the effectiveness was conducted by carrying out both a single study (for the intervention) and a review of the literature (for the comparator). Therefore, power calculations and statistical tests were impossible to perform. Few details of the study population were reported and an explicit control (comparator) group was not considered. In terms of the review of the literature, the estimates obtained from the primary studies were not combined. In addition, the authors stated that primary studies were criticised for several reasons, such as small sample size, lack of differentiation between colon/rectum cancer and low/high risk patients, and no information on quality of life. These issues tend to limit the internal validity of the analysis.
Validity of estimate of measure of benefit The benefit measure was derived from the effectiveness analysis. Benefit was not directly comparable between the single study and the review in that the follow-up period was different. It would have been interesting had the authors adopted a final benefit measure, accounting for quality of life, which appears to be a relevant aspect in the case of the patients included in the analysis.
Validity of estimate of costs The main problem with this study as an economic evaluation was the lack of cost data for any comparator, thus making it impossible to calculate cost-effectiveness as incremental cost per incremental effectiveness. Discounting was not conducted, although relevant, and it was not clear whether a price year was used. Unit costs were reported, but quantities of resources were not. The costs included in the analysis represented reimbursement rates of insurance companies, rather than those reflecting actual resource utilisation. The perspective of the analysis was not clearly reported.
Other issues The issue of the generalisability of the study results to other settings was not addressed and sensitivity analyses were not conducted, therefore limiting the external validity of the study. The authors made few comparisons of their findings with those from other studies and, as already stated, cost results were not given for the studied treatments reviewed in the literature.
Implications of the study The main implication of the study suggested by the authors was that, both the evidence provided by the authors, and the literature review showed that intensive follow-up programmes were not cost-effective. Risk-adapted follow-up programmes appear to represent a more cost-effectiveness alternative. Future research should focus on randomised studies with an explicit control group (no-follow-up arm) and differentiation between rectum/colon and high-/low-risk patients. However, it is clear that, although the paper's title suggests that cost-effectiveness was measured in this paper, cost evidence is lacking, effectiveness evidence is difficult to compare and no incremental analysis was carried out. It would seem that the study could, more usefully, be viewed as an observational study with information on cost.
Bibliographic details Staib L, Link K H, Beger H G. Follow-up in colorectal cancer: cost-effectiveness analysis of established and novel concepts. Langenbeck's Archiv fur Chirugie 2000; 385(6): 412-420 Indexing Status Subject indexing assigned by NLM MeSH Carcinoembryonic Antigen /blood; Colonic Neoplasms /prevention & Colonoscopy /economics; Continuity of Patient Care /economics; Cost-Benefit Analysis; Female; Germany; Humans; Male; Neoplasm Recurrence, Local /prevention & Occult Blood; Randomized Controlled Trials as Topic; Rectal Neoplasms /prevention & Tomography, X-Ray Computed /economics; control; control /economics /surgery; control /economics /surgery AccessionNumber 22000001818 Date bibliographic record published 31/08/2002 Date abstract record published 31/08/2002 |
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