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Biomedical subjects

J Simes

Publications and source records attributed to J Simes.

5 recordsLinked to original sources
PubMed1990

Meta-analysis: its importance in cost-effectiveness studies.

Meta-analysis can be used in cost-effectiveness studies when evidence from several studies is combined to identify which therapies are effective; to estimate the degree of effectiveness between alternative choices; and to estimate cost-related outcomes as part of the costing of therapies and their sequelae. When meta-analysis is performed it is essential that the research protocol include a clear definition of the research question, a description of the studies to be included, inclusion/exclusion criteria for selecting trials, and the methods of trial selection. Issues of bias, and statistical methods and sensitivity analyses used should also be assessed. Meta-analysis, particularly of randomized trials, can provide a rigorous and sound approach to treatment evaluation and should be an integral part of any major cost-effectiveness analysis.

Cost-Benefit Analysis↗
PubMed1990

Prostatic cancer with bone metastases: serum alkaline phosphatase (SAP) as a predictor of response and the significance of the SAP "flare".

The predictive value of serum alkaline phosphatase (SAP) and of prostatic acid phosphatase (PAP) for response to treatment (NPCP criteria) was retrospectively assessed in patients with bone metastases from prostate cancer. Fifty-one patients had SAP measured at the start of treatment and at 1 and 2 months. In 31 of these, corresponding PAP levels were also available at each time point. SAP/PAP profiles at 2 months were classified as "increased" (increment 15% or greater), "decreased" (reduction greater than 15%) or "stable", compared with baseline levels. An additional category, SAP "flare", was also identified (SAP increment greater than 15% at 1 month, with subsequent fall at 2 months). There was a strong association between the SAP profile at 2 months and the response category, whereas the PAP profile at 2 months was more weakly associated. Using results from the 31 patients with both SAP and PAP profiles, the level of SAP was significantly better in predicting the category of response (SAP: sensitivity 94%, specificity 79%; PAP: sensitivity 53%, specificity 57%). An SAP "flare" was associated with response in 8 of 12 patients. An increase in SAP at 1 month is therefore a poor guide to progressive disease and should not be used in isolation to discontinue treatment early. The SAP profile is of value as an earlier predictor of response than X-rays or bone scans and is more reliable than the PAP profile in monitoring patients with prostate cancer and bone metastases.

Acid Phosphatase↗
PubMed1986

Total parenteral nutrition and cancer clinical trials.

Twenty-eight prospective randomized controlled clinical trials evaluating the use of total parenteral nutrition (TPN) in cancer patients were identified through a search of major indexing sources. The data were pooled across studies to increase the ability to detect therapeutic effects. The impact of publication bias and the quality of reporting each trial were used to critically assess the conclusions drawn from the pooled analysis. The authors conclude that TPN may be useful when used preoperatively in patients with gastrointestinal tract cancer. It appears to be beneficial in reducing major surgical complications (pooled P = 0.01) and operative mortality (pooled P = 0.02). No statistically significant benefit from TPN could be demonstrated in survival, treatment tolerance, treatment toxicity, or tumor response in patients receiving chemotherapy or radiotherapy. An increase in the risk of developing an infection in chemotherapy patients given TPN (pooled P less than 0.0001) underscores the importance of demonstrating significant benefits in randomized trials before TPN is used routinely in these patients.

Clinical Trials as Topic↗