Publications

BACKGROUND: Consolidation chemotherapy, autologous hematopoietic cell transplantation (HCT) and allogeneic HCT represent potential treatment alternatives for post-remission therapy in adult acute lymphoblastic leukemia (ALL), but there is genuine uncertainty regarding the optimal approach.

OBJECTIVES: To assess the effect of matched sibling donor vs. no donor status for adults with ALL in first complete remission (CR1).

SEARCH STRATEGY: We performed a search of CENTRAL, MEDLINE and EMBASE electronic databases in September 2010 along with handsearching of literature cited in relevant primary articles, search of abstracts from American Society of Hematology and American Society of Clinical Oncology meetings, as well as consultation with content experts in the field.

SELECTION CRITERIA: Review was performed by two authors, and Inclusion criteria included the following: controlled trials with donor vs. no donor comparison with assignment by genetic randomizationin adults with ALL in CR1.

DATA COLLECTION AND ANALYSIS: We extracted data on benefits (overall survival, progression-free survival) and harms (treatment-related mortality, relapse) of compared treatments. Adverse events were considered, but analysis of individual adverse events was not possible from the reported literature. We pooled summary results from each study using a random-effects model. We assessed heterogeneity. We performed subgroup analyses for disease risk categories. We performed sensitivity analyses according to methodological quality.

MAIN RESULTS: A total of 14 relevant trials were identified, consisting of a total of 3157 patients. There was a statistically significant overall survival advantage in favor of the donor versus no donor group (HR 0.86; 95% CI 0.77 to 0.97; P = 0.01), as well as significant improvement in disease-free survival in the donor group(HR 0.82; 95% CI 0.72 to 0.94; P = 0.004). Those in the donor group had significant reduction in primary disease relapse(RR 0.53; 95% CI 0.37 to 0.76; P = 0.0004) and significant increase in non-relapse mortality(RR 2.8; 95% CI 1.66 to 4.73; P = 0.001). Significant heterogeneity was detected in analysis of relapse (Chi(2) 40.51, df = 6, P < 0.00001; I(2) = 85%). In regard to methodologic quality, the majority of included studies were free of selective reporting, and performed analyses according to intention to treat. Conversely, few reported sample size calculation that informed the study design. While blinding was considered as an important domain of methodological quality, none of the studies reported on whether any of the study personnel were blinded (e.g. subjects, personnel, outcome assessors, data analysts etc). Therefore, we did not consider blinding further in the analysis of methodological quality in this review.

AUTHORS' CONCLUSIONS: The results of this systematic review and meta-analysis support matched sibling donor allogeneic hematopoietic cell transplantation as the optimal post-remission therapy in ALL patients aged 15 years or over. This therapy offers superior overall survival and disease-free survival, and significantly reduces the risk of disease relapse, but does impose an increased risk of non-relapse mortality. Importantly these data are based on adult ALL treated with largely total body irradiation-based myeloablative conditioning and sibling donor transplantation and, therefore, cannot be generalized to pediatric ALL, alternative donors including HLA (human leukocyte antigen) mismatched or unrelated donors, or reduced toxicity or non-myeloablative conditioning regimens.

BACKGROUND: We conducted a systematic review and meta-analysis to assess efficacy and safety of prophylactic HPV vaccines against cervical cancer precursor events in women.

METHODS: Randomized-controlled trials of HPV vaccines were identified from MEDLINE, Cochrane Central Register of Controlled Trials, conference abstracts and references of identified studies, and assessed by two independent reviewers. Efficacy data were synthesized using fixed-effect models, and evaluated for heterogeneity using I2 statistic.

RESULTS: Seven unique trials enrolling 44,142 females were included. The fixed-effect Relative Risk (RR) and 95% confidence intervals were 0.04 (0.01-0.11) and 0.10 (0.03-0.38) for HPV-16 and HPV 18-related CIN2+ in the per-protocol populations (PPP). The corresponding RR was 0.47 (0.36-0.61) and 0.16 (0.08-0.34) in the intention-to-treat populations (ITT). Efficacy against CIN1+ was similar in scale in favor of vaccine. Overall vaccines were highly efficacious against 6-month persistent infection with HPV 16 and 18, both in the PPP cohort (RR: 0.06 [0.04-0.09] and 0.05 [0.03-0.09], respectively), and the ITT cohorts (RR: 0.15 [0.10-0.23] and 0.24 [0.14-0.42], respectively). There was limited prophylactic effect against CIN2+ and 6-month persistent infections associated with non-vaccine oncogenic HPV types. The risk of serious adverse events (RR: 1.00, 0.91-1.09) or vaccine-related serious adverse events (RR: 1.82; 0.79-4.20) did not differ significantly between vaccine and control groups. Data on abnormal pregnancy outcomes were underreported.

CONCLUSIONS: Prophylactic HPV vaccines are safe, well tolerated, and highly efficacious in preventing persistent infections and cervical diseases associated with vaccine-HPV types among young females. However, long-term efficacy and safety needs to be addressed in future trials.

BACKGROUND: Community health workers (CHW) are lay individuals who are trained to serve as liaisons between members of their communities and health care providers and services.

METHODS: A systematic review was conducted to synthesize evidence from all prospective controlled studies on effectiveness of CHW programs in improving screening mammography rates. Studies reported in English and conducted in the United States were included if they: (i) evaluated a CHW intervention designed to increase screening mammography rates in women 40 years of age or older without a history of breast cancer; (ii) were a randomized controlled trial (RCT), case-controlled study, or quasi-experimental study; and (iii) evaluated a CHW intervention outside of a hospital setting.

RESULTS: Participation in a CHW intervention was associated with a statistically significant increase in receipt of screening mammography [risk ratio (RR): 1.06 (favoring intervention); 95% CI: 1.02-1.11, P = 0.003]. The effect remained when pooled data from only RCTs were included in meta-analysis (RR: 1.07; 95% CI: 1.03-1.12, P = 0.0005) but was not present using pooled data from only quasi-experimental studies (RR: 1.03; 95% CI: 0.89-1.18, P = 0.71). In RCTs, participants recruited from medical settings (RR: 1.41; 95% CI: 1.09-1.82, P = 0.008), programs conducted in urban settings (RR: 1.23; 95% CI: 1.09, 1.39, P = 0.001), and programs where CHWs were matched to intervention participants on race or ethnicity (RR: 1.58, 95% CI: 1.29-1.93, P = 0.0001) showed stronger effects on increasing mammography screening rates.

CONCLUSIONS: CHW interventions are effective for increasing screening mammography in certain settings and populations.

IMPACT: CHW interventions are especially associated with improvements in rate of screening mammography in medical settings, urban settings, and in participants who are racially or ethnically concordant with the CHW.

Thalidomide (T) or bortezomib (B) in combination with melphalan plus prednisone (MP) is superior to MP as first line therapy for previously untreated myeloma. However, direct head-to-head comparison of Melphalan, Prednisone plus Bortezomib (MPB) versus Melphalan, Prednisone plus Thalidomide (MPT) is lacking. We performed an indirect meta-analysis to assess the treatment effects of MPB versus MPT via common comparator MP using the systematic review and meta-analytical techniques. A comprehensive literature search (MEDLINE and gray literature) was undertaken. Systematic review was performed as per the Cochrane Collaboration recommendations. Initial search yielded 1,013 citations, of which six randomized controlled trials (RCTs) enrolling 2,798 patients met the inclusion criteria. Comparison of MPT versus MP (five RCTs) showed no survival difference [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.64-1.05] but a statistically significant difference in event-free survival favoring MPT (HR 0.66, 95% CI 0.56-0.77) without excessive treatment-related mortality [risk ratio (RR) 1.11, 95% CI 0.64-1.92]. Comparison of MPB vs. MP (one RCT) showed a statistically significant benefit for survival (HR 0.65, 95% CI 0.51-0.84) and event-free survival (HR 0.48, 95% CI 0.37-0.63) without difference in treatment-related mortality (RR 0.42, 95% CI 0.11-1.63) with MPB. The indirect comparison of MPB versus MPT showed no difference between MPB versus MPT for all outcomes but a significant benefit for complete response (RR 2.34, 95% CI 1.12-4.90), and grade III/IV adverse events (RR 0.53, 95% CI 0.38-0.73) favoring MPB. There is an uncertainty about definitive superiority of one type of regimen over the other. Therefore, direct head-to-head comparison between these competing regimens is warranted.

Individual studies rarely provide definitive answers to questions related to the effects of treatments. Whether the treatment is associated with more good than harm is best answered by considering the totality of evidence on the topic through the methodology of systematic reviews. The objective of this overview is to summarize all existing systematic reviews on treatments in multiple myeloma (MM), which accounts for 14% of new cases of hematological malignancies each year. Therefore, MEDLINE and the Cochrane Database of Systematic Reviews were systematically searched to identify systematic reviews of interventions. Data were extracted on patients, interventions, control and outcomes. Methodological quality of the systematic reviews was assessed using the AMSTAR assessment tool. Eleven systematic reviews on treatment of MM were included in the overview. Ten addressed seven unique questions and also performed a meta-analysis. One addressed 21 clinical questions related to treatment decisions in myeloma. The quality of systematic reviews varied. The results from the overview show that early treatment does not offer survival benefit. Thalidomide is associated with improved survival when added to standard chemotherapy regimens as induction or maintenance therapy but at the expense of an increased risk of serious adverse events, such as venous thromboembolism. High-dose therapy with single autologous hematopoietic stem cell transplant (AHCT) is associated with superior event-free but not overall survival compared to chemotherapy. Tandem AHCT does not prolong survival but is associated with better event-free survival in comparison to single AHCT. In addition, combination treatment with bisphosphonates reduces pathological vertebral fractures and pain, but does not prolong survival. We found no systematic review evaluating the effects of other novel agents, such as bortezomib or lenalidomide, as single agents or in combinations. Several key clinical questions have been successfully answered by conducting systematic reviews. However, currently many questions of importance for the management of patients with myeloma continue to be dealt with in individual studies instead of synthesized evidence. There is urgent need to perform research synthesis of data related to the effects of novel agents.

OBJECTIVE: Optimism bias refers to unwarranted belief in the efficacy of new therapies. We assessed the impact of optimism bias on a proportion of trials that did not answer their research question successfully and explored whether poor accrual or optimism bias is responsible for inconclusive results.

STUDY DESIGN: Systematic review.

SETTING: Retrospective analysis of a consecutive-series phase III randomized controlled trials (RCTs) performed under the aegis of National Cancer Institute Cooperative groups.

RESULTS: Three hundred fifty-nine trials (374 comparisons) enrolling 150,232 patients were analyzed. Seventy percent (262 of 374) of the trials generated conclusive results according to the statistical criteria. Investigators made definitive statements related to the treatment preference in 73% (273 of 374) of studies. Investigators' judgments and statistical inferences were concordant in 75% (279 of 374) of trials. Investigators consistently overestimated their expected treatment effects but to a significantly larger extent for inconclusive trials. The median ratio of expected and observed hazard ratio or odds ratio was 1.34 (range: 0.19-15.40) in conclusive trials compared with 1.86 (range: 1.09-12.00) in inconclusive studies (P<0.0001). Only 17% of the trials had treatment effects that matched original researchers' expectations.

CONCLUSION: Formal statistical inference is sufficient to answer the research question in 75% of RCTs. The answers to the other 25% depend mostly on subjective judgments, which at times are in conflict with statistical inference. Optimism bias significantly contributes to inconclusive results.

BACKGROUND: Despite the well documented advantages of hospice care, most terminally ill patients do not reap the maximum benefit from hospice services, with the majority of them receiving hospice care either prematurely or delayed. Decision systems to improve the hospice referral process are sorely needed.

METHODS: We present a novel theoretical framework that is based on well-established methodologies of prognostication and decision analysis to assist with the hospice referral process for terminally ill patients. We linked the SUPPORT statistical model, widely regarded as one of the most accurate models for prognostication of terminally ill patients, with the recently developed regret based decision curve analysis (regret DCA). We extend the regret DCA methodology to consider harms associated with the prognostication test as well as harms and effects of the management strategies. In order to enable patients and physicians in making these complex decisions in real-time, we developed an easily accessible web-based decision support system available at the point of care.

RESULTS: The web-based decision support system facilitates the hospice referral process in three steps. First, the patient or surrogate is interviewed to elicit his/her personal preferences regarding the continuation of life-sustaining treatment vs. palliative care. Then, regret DCA is employed to identify the best strategy for the particular patient in terms of threshold probability at which he/she is indifferent between continuation of treatment and of hospice referral. Finally, if necessary, the probabilities of survival and death for the particular patient are computed based on the SUPPORT prognostication model and contrasted with the patient's threshold probability. The web-based design of the CDSS enables patients, physicians, and family members to participate in the decision process from anywhere internet access is available.

CONCLUSIONS: We present a theoretical framework to facilitate the hospice referral process. Further rigorous clinical evaluation including testing in a prospective randomized controlled trial is required and planned.

We present a novel knowledge discovery methodology that relies on Rough Set Theory to predict the life expectancy of terminally ill patients in an effort to improve the hospice referral process. Life expectancy prognostication is particularly valuable for terminally ill patients since it enables them and their families to initiate end-of-life discussions and choose the most desired management strategy for the remainder of their lives. We utilize retrospective data from 9105 patients to demonstrate the design and implementation details of a series of classifiers developed to identify potential hospice candidates. Preliminary results confirm the efficacy of the proposed methodology. We envision our work as a part of a comprehensive decision support system designed to assist terminally ill patients in making end-of-life care decisions.

Chronic diseases such as diabetes and heart disease are the leading causes of disability and death in the developed world. Technological interventions such as mobile applications have the ability to facilitate and motivate patients in chronic disease management, but these types of interventions present considerable design challenges. The primary objective of this paper is to present the challenges arising from the design and implementation of software applications aiming to assist patients in chronic disease management. We also outline preliminary results regarding a self-management application currently under development targeting young adults suffering from type 1 diabetes.

Controlled clinical trials are widely considered to be the vehicle to treatment discovery in cancer that leads to significant improvements in health outcomes including an increase in life expectancy. We have previously shown that the pattern of therapeutic discovery in randomized controlled trials (RCTs) can be described by a power law distribution. However, the mechanism generating this pattern is unknown. Here, we propose an explanation in terms of the social relations between researchers in RCTs. We use social network analysis to study the impact of interactions between RCTs on treatment success. Our dataset consists of 280 phase III RCTs conducted by the NCI from 1955 to 2006. The RCT networks are formed through trial interactions formed i) at random, ii) based on common characteristics, or iii) based on treatment success. We analyze treatment success in terms of survival hazard ratio as a function of the network structures. Our results show that the discovery process displays power law if there are preferential interactions between trials that may stem from researchers' tendency to interact selectively with established and successful peers. Furthermore, the RCT networks are "small worlds": trials are connected through a small number of ties, yet there is much clustering among subsets of trials. We also find that treatment success (improved survival) is proportional to the network centrality measures of closeness and betweenness. Negative correlation exists between survival and the extent to which trials operate within a limited scope of information. Finally, the trials testing curative treatments in solid tumors showed the highest centrality and the most influential group was the ECOG. We conclude that the chances of discovering life-saving treatments are directly related to the richness of social interactions between researchers inherent in a preferential interaction model.