Otavio Augusto Camara Clark

Pharmaceutical industry sponsorship and research outcome and quality: systematic review

Abstract Objective To investigate whether funding of drug studies by the pharmaceutical industry is associated with outcomes that are favourable to the funder and whether the methods of trials funded by pharmaceutical companies differ from the methods in trials with other sources of support. Methods Medline (January 1966 to December 2002) and Embase (January 1980 to December 2002) searches were supplemented with material identified in the references and in the authors personal files. Data were independently abstracted by three of the authors and disagreements were resolved by consensus. Results 30 studies were included. Research funded by drug companies was less likely to be published than research funded by other sources. Studies sponsored by pharmaceutical companies were more likely to have outcomes favouring the sponsor than were studies with other sponsors (odds ratio 4.05; 95% confidence interval 2.98 to 5.51; 18 comparisons). None of the 13 studies that analysed methods reported that studies funded by industry was of poorer quality. Conclusion Systematic bias favours products which are made by the company funding the research. Explanations include the selection of an inappropriate comparator to the product being investigated and publication bias.

Bisphosphonates in multiple myeloma

BACKGROUNDnMultiple myeloma is a disease characterized by the neoplastic proliferation of a clone of plasma cells that can lead to bone destruction. Bisphosphonates are specific inhibitors of osteoclastic activity. Therefore, there is a pharmacological basis for their use in multiple myeloma. However, the exact clinical role of bisphosphonates in multiple myeloma remains unclear.nnnOBJECTIVESnPrimary: to determine whether adding bisphosphonates to standard therapy in multiple myeloma decreases skeletal-related morbidity (pathological fractures), skeletal-related mortality and overall mortality. Secondary: to determine the effects of bisphosphonates on pain, quality of life and incidence of hypercalcemia.nnnSEARCH STRATEGYnWe searched MEDLINE (1966 - June 2001), LILACS (1982 - June 2001), EMBASE (1974 - December 2000) and the Cochrane Controlled Trials Register (all years, latest Issue 03/2001) to identify all randomized trials in multiple myeloma. All of these references were accessed in order to identify trials related to the use of bisphosphonates in myeloma. All relevant references in each article were also scanned. We also performed a handsearch of relevant meeting proceedings from 1993 to 2000. Additionally, manufacturers of bisphosphonates and researchers in the field were contacted.nnnSELECTION CRITERIAnRandomised trials with a parallel design on the use of bisphosphonate in myeloma compared with placebo or no treatment as a control group.nnnDATA COLLECTION AND ANALYSISnTwo reviewers independently assessed trial eligibility, methodological quality and abstracted data. A third reviewer checked all data after the extraction was completed. Statistical heterogeneity was tested using random and fixed effect models. All pooled data are reported using Peto odds ratios and, when appropriate, as absolute risk reduction and the number needed to treat to prevent or to cause a pathological event.nnnMAIN RESULTSnEleven trials were included with 1113 patients analysed in bisphosphonates groups, and 1070 analysed in control groups. There was no significant statistical heterogeneity among trials for the endpoints selected for comparison in this review. The pooled analysis of the published evidence demonstrated the beneficial effect of bisphosphonates on prevention of pathological vertebral fractures [OR=0.59 (95% confidence interval (CI) 0.45-0.78); P=0.0001] and on amelioration of pain [OR = 0.59 (95%CI 0.46-0.76); P=0.00005]. However, the analysis of the effect of bisphosphonates on pain was based on clinically heterogeneous data and must be interpreted with caution. Although there was no statistical heterogeneity between groups, the benefit was most apparent with clodronate and pamidronate. In absolute terms, the result may be interpreted to mean that 10 (95%CI 7-20) patients with multiple myeloma should be treated to prevent one vertebral fracture, and 11 (95%CI 7-28) to prevent one patient experiencing pain. We found no significant effect of bisphosphonates on mortality, on the reduction of non-vertebral fractures or on the incidence of hypercalcemia. There were no significant adverse effects associated with the administration of bisphosphonates. Our results are based on the extraction of published data, which were sometimes poorly reported, and thus the results should be understood as the best possible summation of available evidence.nnnREVIEWERS CONCLUSIONSnAdding bisphosphonates to the treatment of myeloma reduces pathological vertebral fractures and pain but - from the published evidence - not mortality. On current evidence, clodronate or pamidronate may be the preferred agents.

Colony‐stimulating factors for chemotherapy‐induced febrile neutropenia

BACKGROUNDnFebrile neutropenia is a frequent adverse event experienced by people with cancer who are undergoing chemotherapy, and is a potentially life-threatening situation. The current treatment is supportive care plus antibiotics. Colony-stimulating factors (CSFs), such as granulocyte-CSF (G-CSF) and granulocyte-macrophage CSF (GM-CSF), are cytokines that stimulate and accelerate the production of one or more cell lines in the bone marrow. Clinical trials have addressed the question of whether the addition of a CSF to antibiotics could improve outcomes in individuals diagnosed with febrile neutropenia. However, the results of these trials are conflicting.nnnOBJECTIVESnTo evaluate the safety and efficacy of adding G-CSF or GM-CSF to standard treatment (antibiotics) when treating chemotherapy-induced febrile neutropenia in individuals diagnosed with cancer.nnnSEARCH METHODSnWe conducted the search in March 2014 and covered the major electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, and SCI. We contacted experts in hematology and oncology and also scanned the citations from the relevant articles.nnnSELECTION CRITERIAnWe searched for randomized controlled trials (RCTs) that compared CSF plus antibiotics versus antibiotics alone for the treatment of chemotherapy-induced febrile neutropenia in adults and children.nnnDATA COLLECTION AND ANALYSISnWe used the standard methodological procedures expected by The Cochrane Collaboration. We performed meta-analysis of the selected studies using Review Manager 5 software.nnnMAIN RESULTSnFourteen RCTs (15 comparisons) including a total of 1553 participants addressing the role of CSF plus antibiotics in febrile neutropenia were included. Overall mortality was not improved by the use of CSF plus antibiotics versus antibiotics alone (hazard ratio (HR) 0.74 (95% confidence interval (CI) 0.47 to 1.16) P = 0.19; 13 RCTs; 1335 participants; low quality evidence). A similar finding was seen for infection-related mortality (HR 0.75 (95% CI 0.47 to 1.20) P = 0.23; 10 RCTs; 897 participants; low quality evidence). Individuals who received CSF plus antibiotics were less likely to be hospitalized for more than 10 days (risk ratio (RR) 0.65 (95% CI 0.44 to 0.95) P = 0.03; 8 RCTs; 1221 participants; low quality evidence) and had more number of participants with a more faster neutrophil recovery (RR 0.52 (95% CI 0.34 to 0.81) P = 0.004; 5 RCTs; 794 participants; moderate quality evidence) than those treated with antibiotics alone. Similarly, participants receiving CSF plus antibiotics had shorter duration of neutropenia (standardized mean difference (SMD) -1.70 (95% CI -2.65 to -0.76) P = 0.0004; 9 RCTs; 1135 participants; moderate quality evidence), faster recovery from fever (SMD -0.49 (95% CI -0.90 to -0.09) P value = 0.02; 9 RCTs; 966 participants; moderate quality evidence) and shorter duration of antibiotics use (SMD -1.50 (95% CI -2.83 to -0.18) P = 0.03; 3 RCTs; 457 participants; low quality evidence) compared with participants receiving antibiotics alone. We found no significant difference in the incidence of deep venous thromboembolism (RR 1.68 (95% CI 0.72 to 3.93) P = 0.23; 4 RCTs; 389 participants; low quality evidence) in individuals treated with CSF plus antibiotics compared with those treated with antibiotics alone. We found higher incidence of bone or joint pain or flu-like symptoms (RR 1.59 (95% CI 1.04 to 2.42) P = 0.03; 6 RCTs; 622 participants; low quality evidence) in individuals treated with CSF plus antibiotics compared with those treated with antibiotics alone. Overall, the methodological quality of studies was moderate to low across different outcomes. The main reasons to downgrade the quality of evidence were inconsistency across the included studies and imprecision of results.nnnAUTHORS CONCLUSIONSnThe use of a CSF plus antibiotics in individuals with chemotherapy-induced febrile neutropenia had no effect on overall mortality, but reduced the amount of time participants spent in hospital and improved their ability to achieve neutrophil recovery. It was not clear whether CSF plus antibiotics had an effect on infection-related mortality. Participants receiving CSFs had shorter duration of neutropenia, faster recovery from fever and shorter duration of antibiotics use.

Bisphosphonates in multiple myeloma: a network meta-analysis

BACKGROUNDnBisphosphonates are specific inhibitors of osteoclastic activity and used in the treatment of patients with multiple myeloma (MM). While bisphosphonates are shown to be effective in reducing vertebral fractures and pain, their role in improving overall survival (OS) remains unclear. This is an update of a Cochrane review first published in 2002 and previously updated in 2010.nnnOBJECTIVESnTo assess the evidence related to benefits and harms associated with use of various types of bisphosphonates (aminobisphosphonates versus nonamino bisphosphonates) in the management of patients with MM. Our primary objective was to determine whether adding bisphosphonates to standard therapy in MM improves OS and progression-free survival (PFS), and decreases skeletal-related morbidity. Our secondary objectives were to determine the effects of bisphosphonates on pain, quality of life, incidence of hypercalcemia, incidence of bisphosphonate-related gastrointestinal toxicities, osteonecrosis of jaw and hypocalcemia.nnnSEARCH METHODSnWe searched MEDLINE, LILACS, EMBASE (December 2009 to October 2011) and the Cochrane Controlled Trials Register (all years, latest Issue September 2011) to identify all randomized trials in MM up to October 2011 using a combination of text and MeSH terms. We also handsearched relevant meeting proceedings (December 2009 to October 2011).nnnSELECTION CRITERIAnAny randomized controlled trial (RCT) assessing the role of bisphosphonates and observational studies or case reports examining bisphosphonate-related osteonecrosis of the jaw in patients with MM were eligible for inclusion.nnnDATA COLLECTION AND ANALYSISnTwo review authors extracted the data. Data were pooled and reported as hazard ratio (HR) or risk ratio (RR) under a random-effects model. Statistical heterogeneity was explored using metaregression.nnnMAIN RESULTSnIn this update, we included 2 studies (2464 patients) that were not part of our last Cochrane review published in 2010. In this review we included 16 RCTs comparing bisphosphonates with either placebo or no treatment and 4 RCTs with a different bisphosphonate as a comparator. The 20 included RCTs enrolled 6692 patients. Overall methodological quality of reporting was moderate. Thirty per cent (6/20) of trials reported the method of generating the randomization sequence. Forty per cent (8/20) of trials had adequate allocation concealment. Withdrawals and dropouts were described in 60% (12/20) of trials. Pooled results showed no direct effect of bisphosphonates on OS compared with placebo or no treatment (HR 0.96, 95% CI 0.82 to 1.13; P = 0.64). However, there was a statistically significant heterogeneity among the included RCTs (I(2) = 55%, P = 0.01) for OS. To explain this heterogeneity we performed a metaregression assessing the relationship between bisphosphonate potency and improvement in OS, which found indicating an OS benefit with zoledronate (P = 0.058). This provided a further rationale for performing network meta-analyses of the various types of bisphosphonates that were not compared head to head in RCTs. Results from network meta-analyses showed superior OS with zoledronate compared with etidronate (HR 0.43, 95% CI 0.16 to 0.86) and placebo (HR 0.61, 95% CI 0.28 to 0.98). However, there was no difference between zoledronate and other bisphosphonates. Pooled analysis did not demonstrate a beneficial effect of bisphosphonates compared with placebo or no treatment in improving PFS (HR 0.70, 95% CI 0.41 to 1.19; P = 0.18) There was no heterogeneity among trials reporting PFS estimates (I(2) = 35%, P = 0.20).Pooled analysis demonstrated a beneficial effect of bisphosphonates compared with placebo or no treatment on prevention of pathological vertebral fractures (RR 0.74, 95% CI 0.62 to 0.89; I(2) = 7%), skeletal-related events (SRE) (RR 0.80, 95% CI 0.72 to 0.89; I(2) = 2%) and amelioration of pain (RR 0.75, 95% CI 0.60 to 0.95; I(2) = 63%). The network meta-analysis did not show any difference in the incidence of osteonecrosis of the jaw (5 RCTs, 3198 patients) between bisphosphonates. Rates of osteonecrosis of the jaw in observational studies (9 studies, 1400 patients) ranged from 0% to 51%. The pooled results (6 RCTs, 1689 patients) showed no statistically significant increase in frequency of gastrointestinal symptoms with the use of bisphosphonates compared with placebo or no treatment (RR 1.23, 95% CI 0.95 to 1.60; P = 0.11).The pooled results (3 RCTs, 1002 patients) showed no statistically significant increase in frequency of hypocalcemia with the use of bisphosphonates compared with placebo or no treatment (RR 2.19, 95% CI 0.49 to 9.74). The network meta-analysis did not show any differences in the incidence of hypocalcemia, renal dysfunction and gastrointestinal toxicity between the bisphosphonates used.nnnAUTHORS CONCLUSIONSnUse of bisphosphonates in patients with MM reduces pathological vertebral fractures, SREs and pain. Assuming a baseline risk of 20% to 50% for vertebral fracture without treatment, between 8 and 20 MM patients should be treated to prevent vertebral fracture(s) in one patient. Assuming a baseline risk of 31% to 76% for pain amelioration without treatment, between 5 and 13 MM patients should be treated to reduce pain in one patient. With a baseline risk of 35% to 86% for SREs without treatment, between 6 and 15 MM patients should be treated to prevent SRE(s) in one patient. Overall, there were no significant adverse effects associated with the administration of bisphosphonates identified in the included RCTs. We found no evidence of superiority of any specific aminobisphosphonate (zoledronate, pamidronate or ibandronate) or nonaminobisphosphonate (etidronate or clodronate) for any outcome. However, zoledronate appears to be superior to placebo and etidronate in improving OS.

Quality and methods of developing practice guidelines.

BackgroundIt is not known whether there are differences in the quality and recommendations between evidence-based (EB) and consensus-based (CB) guidelines. We used breast cancer guidelines as a case study to assess for these differences.MethodsFive different instruments to evaluate the quality of guidelines were identified by a literature search. We also searched MEDLINE and the Internet to locate 8 breast cancer guidelines. These guidelines were classified in three categories: evidence based, consensus based and consensus based with no explicit consideration of evidence (CB-EB). Each guideline was evaluated by three of the authors using each of the instruments. For each guideline we assessed the agreement among 14 decision points which were selected from the NCCN (National Cancer Comprehensive Network) guidelines algorithm. For each decision point we recorded the level of the quality of the information used to support it. A regression analysis was performed to assess if the percentage of high quality evidence used in the guidelines development was related to the overall quality of the guidelines.ResultsThree guidelines were classified as EB, three as CB-EB and two as CB. The EB guidelines scored better than CB, with the CB-EB scoring in the middle among all instruments for guidelines quality assessment. No major disagreement in recommendations was detected among the guidelines regardless of the method used for development, but the EB guidelines had a better agreement with the benchmark guideline for any decision point. When the source of evidence used to support decision were of high quality, we found a higher level of full agreement among the guidelines recommendations. Up to 94% of variation in the quality score among guidelines could be explained by the quality of evidence used for guidelines development.ConclusionEB guidelines have a better quality than CB guidelines and CB-EB guidelines. Explicit use of high quality evidence can lead to a better agreement among recommendations. However, no major disagreement among guidelines was noted regardless of the method for their development.

Erythropoietin, uncertainty principle and cancer related anaemia

BackgroundThis study was designed to evaluate if erythropoietin (EPO) is effective in the treatment of cancer related anemia, and if its effect remains unchanged when data are analyzed according to various clinical and methodological characteristics of the studies. We also wanted to demonstrate that cumulative meta-analysis (CMA) can be used to resolve uncertainty regarding clinical questions.MethodsSystematic Review (SR) of the published literature on the role of EPO in cancer-related anemia. A cumulative meta-analysis (CMA) using a conservative approach was performed to determine the point in time when uncertainty about the effect of EPO on transfusion-related outcomes could be considered resolved. Participants: Patients included in randomized studies that compared EPO versus no therapy or placebo. Main outcome measures: Number of patients requiring transfusions.ResultsNineteen trials were included. The pooled results indicated a significant effect of EPO in reducing the number of patients requiring transfusions [odds ratio (OR) = 0.41; 95%CI: 0.33 to 0.5; p < 0.00001;relative risk (RR) = 0.61; 95% CI: 0.54 to 0.68]. The results remain unchanged after the sensitivity analyses were performed according to the various clinical and methodological characteristics of the studies. The heterogeneity was less pronounced when OR was used instead of RR as the measure of the summary point estimate. Analysis according to OR was not heterogeneous, but the pooled RR was highly heterogeneous. A stepwise metaregression analysis did point to the possibility that treatment effect could have been exaggerated by inadequacy in allocation concealment and that larger treatment effects are seen at hb level > 11.5 g/dl. We identified 1995 as the point in time when a statistically significant effect of EPO was demonstrated and after which we considered that uncertainty about EPO efficacy was resolved.ConclusionEPO is effective in the treatment of anemia in cancer patients. This could have already been known in 1995 if a CMA had been performed at that time.