Verena Roloff

MRC Mitochondrial Biology Unit, Cambridge, England, United Kingdom

Are you Verena Roloff?

Claim your profile

Publications (4)19.85 Total impact

  • Source
    Verena Roloff · Julian P T Higgins · Alex J Sutton
    [Show abstract] [Hide abstract]
    ABSTRACT: Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method based on conditional power to make these recommendations more specific. Assuming a random-effects meta-analysis model, we evaluate the influence of the number of additional studies, of their information sizes and of the heterogeneity anticipated among them on the ability of an updated meta-analysis to detect a prespecified effect size. The conditional powers of possible design alternatives can be summarized in a simple graph which can also be the basis for decision making. We use three examples from the Cochrane Database of Systematic Reviews to demonstrate our strategy. We demonstrate that if heterogeneity is anticipated, it might not be possible for a single study to reach the desirable power no matter how large it is. Copyright © 2012 John Wiley & Sons, Ltd.
    Statistics in Medicine 01/2013; 32(1). DOI:10.1002/sim.5524 · 2.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Chronic lymphocytic leukaemia (CLL) accounts for 25% of all leukaemias and is the most common lymphoid malignancy in western countries. Standard treatments include mono- or polychemotherapies, usually combined with monoclonal antibodies such as rituximab or alemtuzumab. However, the impact of these agents remains unclear, as there are hints for increased risk of severe infections. OBJECTIVES: The objectives of this review are to provide an evidence-based answer regarding the clinical benefits and harms of monoclonal anti-CD20 antibodies (such as rituximab, ofatumumab, GA101) compared to no further therapy or to other anti-leukaemic therapies in patients with CLL, irrespective of disease status. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 12, 2011), MEDLINE (from January 1990 to 4 January 2012), and EMBASE (from 1990 to 20 March 2009) as well as conference proceedings (American Society of Hematology, American Society of Clinical Oncology, European Hematology Association and European Society of Medical Oncology) for randomised controlled trials (RCTs). SELECTION CRITERIA: We included RCTs examining monoclonal anti-CD20 antibodies compared to no further therapy or to anti-leukaemic therapy such as chemotherapy or monoclonal antibodies in patients with newly diagnosed or relapsed CLL. DATA COLLECTION AND ANALYSIS: We used hazard ratios (HR) as effect measures for overall survival (OS), progression-free survival (PFS) and time to next treatment, and risk ratios (RR) for response rates, treatment-related mortality (TRM) and adverse events (AEs). Two review authors independently extracted data and assessed quality of trials. MAIN RESULTS: We screened a total of 1150 records. Seven RCTs involving 1763 patients were identified, but only five could be included in the two separate meta-analyses we performed. We judged the overall the quality of these trials as moderate to high. All trials were randomised and open-label studies. However, two trials were published as abstracts only, therefore we were unable to assess the potential risk of bias for these trials in detail.Three RCTs (N = 1421) assessed the efficacy of monoclonal anti-CD20 antibodies (i.e. rituximab) plus chemotherapy compared to chemotherapy alone. The meta-analyses showed a statistically significant OS (HR 0.78, 95% confidence interval (CI) 0.62 to 0.98, P = 0.03, the number needed to treat for an additional beneficial effect (NNTB) was 12) and PFS (HR 0.64, 95% CI 0.55 to 0.74, P < 0.00001) advantage for patients receiving rituximab. In the rituximab-arm occurred more AEs, World Health Organization (WHO) grade 3 or 4 (3 trials, N = 1398, RR 1.15, 95% CI 1.08 to 1.23, P < 0.0001; the number needed to harm for an additional harmful outcome (NNTH) was 9), but that did not lead to a statistically significant difference regarding TRM (3 trials, N = 1415, RR 1.19, 95% CI 0.70 to 2.01, P = 0.52).Two trials (N = 177) evaluated rituximab versus alemtuzumab. Neither study reported OS or PFS. There was no statistically significant difference between arms regarding complete response rate (CRR) (RR 1.21, 95% CI 0.94 to 1.58, P = 0.14) or TRM (RR 0.31, 95% CI 0.06 to 1.51, P = 0.15). However, the CLL2007FMP trial was stopped early owing to an increase in mortality in the alemtuzumab arm. More serious AEs occurred in this arm (43% with alemtuzumab versus 22% with rituximab; P = 0.006).Two trials assessed different dosages or time schedules of monoclonal anti-CD20 antibodies. One trial (N = 104) evaluated two different rituximab schedules (concurrent arm: fludarabine plus rituximab (Flu-R) plus rituximab consolidation versus sequential arm: fludarabine alone plus rituximab consolidation). The comparison of the concurrent versus sequential regimen of rituximab showed a statistically significant difference of the CRR with 33% in the concurrent-arm and 15% in the sequential-arm (P = 0.04), that did not lead to statistically significant differences regarding OS (HR 1.14, 95% CI 0.20 to 6.65, P = 0.30) or PFS (HR 0.96, 95% CI 0.43 to 2.15, P = 0.11). Furthermore results showed no differences in occurring AEs, except for neutropenia, which was more often observed in patients of the concurrent arm. The other trial (N = 61) investigated two different dosages (500 mg and 1000 mg) of ofatumumab in addition to FluC. The arm investigating ofatumumab did not assess OS and a median PFS had not been reached owing to the short median follow-up of eight months. It showed no statistically significant differences between arms regarding CRR (32% in the FCO500 arm versus 50% in the FCO1000 arm; P = 0.10) or AEs (anaemia, neutropenia, thrombocytopenia). AUTHORS' CONCLUSIONS: This meta-analysis showed that patients receiving chemotherapy plus rituximab benefit in terms of OS as well as PFS compared to those with chemotherapy alone. Therefore, it supports the recommendation of rituximab in combination with FluC as an option for the first-line treatment as well as for the people with relapsed or refractory CLL. The available evidence regarding the other assessed comparisons was not sufficient to deduct final conclusions.
    Cochrane database of systematic reviews (Online) 11/2012; 11(11):CD008079. DOI:10.1002/14651858.CD008079.pub2 · 5.94 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Parental psychosocial health can have a significant effect on the parent-child relationship, with consequences for the later psychological health of the child. Parenting programmes have been shown to have an impact on the emotional and behavioural adjustment of children, but there have been no reviews to date of their impact on parental psychosocial wellbeing. To address whether group-based parenting programmes are effective in improving parental psychosocial wellbeing (for example, anxiety, depression, guilt, confidence). We searched the following databases on 5 December 2012: CENTRAL (2011, Issue 4), MEDLINE (1950 to November 2011), EMBASE (1980 to week 48, 2011), BIOSIS (1970 to 2 December 2011), CINAHL (1982 to November 2011), PsycINFO (1970 to November week 5, 2011), ERIC (1966 to November 2011), Sociological Abstracts (1952 to November 2011), Social Science Citation Index (1970 to 2 December 2011), metaRegister of Controlled Trials (5 December 2011), NSPCC Library (5 December 2011). We searched ASSIA (1980 to current) on 10 November 2012 and the National Research Register was last searched in 2005. We included randomised controlled trials that compared a group-based parenting programme with a control condition and used at least one standardised measure of parental psychosocial health. Control conditions could be waiting-list, no treatment, treatment as usual or a placebo. At least two review authors extracted data independently and assessed the risk of bias in each study. We examined the studies for any information on adverse effects. We contacted authors where information was missing from trial reports. We standardised the treatment effect for each outcome in each study by dividing the mean difference in post-intervention scores between the intervention and control groups by the pooled standard deviation. We included 48 studies that involved 4937 participants and covered three types of programme: behavioural, cognitive-behavioural and multimodal. Overall, we found that group-based parenting programmes led to statistically significant short-term improvements in depression (standardised mean difference (SMD) -0.17, 95% confidence interval (CI) -0.28 to -0.07), anxiety (SMD -0.22, 95% CI -0.43 to -0.01), stress (SMD -0.29, 95% CI -0.42 to -0.15), anger (SMD -0.60, 95% CI -1.00 to -0.20), guilt (SMD -0.79, 95% CI -1.18 to -0.41), confidence (SMD -0.34, 95% CI -0.51 to -0.17) and satisfaction with the partner relationship (SMD -0.28, 95% CI -0.47 to -0.09). However, only stress and confidence continued to be statistically significant at six month follow-up, and none were significant at one year. There was no evidence of any effect on self-esteem (SMD -0.01, 95% CI -0.45 to 0.42). None of the trials reported on aggression or adverse effects.The limited data that explicitly focused on outcomes for fathers showed a statistically significant short-term improvement in paternal stress (SMD -0.43, 95% CI -0.79 to -0.06). We were unable to combine data for other outcomes and individual study results were inconclusive in terms of any effect on depressive symptoms, confidence or partner satisfaction. The findings of this review support the use of parenting programmes to improve the short-term psychosocial wellbeing of parents. Further input may be required to ensure that these results are maintained. More research is needed that explicitly addresses the benefits for fathers, and that examines the comparative effectiveness of different types of programme along with the mechanisms by which such programmes bring about improvements in parental psychosocial functioning.
    Cochrane database of systematic reviews (Online) 06/2012; 6(5):CD002020. DOI:10.1002/14651858.CD002020.pub3 · 5.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chronic lymphocytic leukaemia (CLL) accounts for 25% of all leukaemias and is the most common lymphoid malignancy in Western countries. Standard treatment includes mono- or poly-chemotherapies. Nowadays, monoclonal antibodies are added, especially alemtuzumab and rituximab. However, the impact of these agents remains unclear, as there are hints of an increased risk of severe infections. To assess alemtuzumab compared with no further therapy, or with other anti-leukaemic therapy in patients with CLL. We searched CENTRAL and MEDLINE (from January 1985 to November 2011), and EMBASE (from 1990 to 2009) as well as conference proceedings for randomised controlled trials (RCTs). Two review authors (KB, NS) independently screened search results. We included RCTs comparing alemtuzumab with no further therapy or comparing alemtuzumab with anti-leukaemic therapy such as chemotherapy or monoclonal antibodies in patients with histologically-confirmed B-cell CLL. Both pretreated and chemotherapy-naive patients were included. We used hazard ratios (HR) as an effect measure for overall survival (OS) and progression-free survival (PFS) and risk ratios (RRs) for response rates, treatment-related mortality (TRM) and adverse events. Two review authors independently extracted data and assessed the quality of trials. Our search strategies led to 1542 potentially relevant references. Of these, we included five RCTs involving 845 patients. Overall, we judged the quality of the five trials as moderate. All trials were reported as randomised and open-label studies. However, two trials were published as abstracts only, therefore, we were unable to assess the potential risk of bias for these trials in detail. Because of the small number of studies in each analysis (two), the quantification of heterogeneity was not reliable.Two trials (N = 356) assessed the efficacy of alemtuzumab compared with no further therapy. One trial (N = 335), reported a statistically significant OS advantage for all patients receiving alemtuzumab (HR 0.65 (95% confidence interval (CI) 0.45 to 0.94; P = 0.021). However, no improvement was seen for the subgroup of patients in Rai stage I or II (HR 1.07; 95% CI 0.62 to 1.84; P = 0.82). In both trials, the complete response rate (CRR) (RR 2.61; 95% CI 1.26 to 5.42; P = 0.01) and PFS (HR 0.58; 95% CI 0.44 to 0.76; P < 0.0001) were statistically significantly increased under therapy with alemtuzumab. The potential heterogeneity seen in the forest plot could be due to the different study designs: One trial evaluated alemtuzumab additional to fludarabine as relapse therapy; the other trial examined alemtuzumab compared with no further therapy for consolidation after first remission.There was no statistically significant difference for TRM between both arms (RR 0.57; 95% CI 0.17 to 1.90; P = 0.36). A statistically significant higher rate of CMV reactivation (RR 10.52; 95% CI 1.42 to 77.68; P = 0.02) and infections (RR 1.32; 95% CI 1.01 to 1.74; P = 0.04) occurred in patients receiving alemtuzumab. Seven severe infections (64%) in the alemtuzumab arm in the GCLLSG CLL4B study led to premature closure.Two trials (N = 177), evaluated alemtuzumab versus rituximab. Neither study reported OS or PFS. We could not detect a statistically significant difference for CRR (RR 0.85; 95% CI 0.67 to 1.08; P = 0.18) or TRM (RR 3.20; 95% CI 0.66 to 15.50; P = 0.15) between both arms. However, the CLL2007FMP trial was stopped early due to an increase in mortality in the alemtuzumab arm. More serious adverse events occurred in this arm (43% versus 22% (rituximab), P = 0.006).One trial (N = 297), assessed the efficacy of alemtuzumab compared with chemotherapy (chlorambucil). For this trial, no HR is reported for OS. Median survival has not yet been reached, 84% of patients were alive in each arm at the data cut-off or at the last follow-up date (24.6 months). The TRM between arms shows no statistical significant difference (0.6% versus 2.0%; P = 0.34). Alemtuzumab statistically significantly improves PFS (HR 0.58; 95% CI 0.43 to 0.77; P = 0.0001), time to next treatment (23.3 compared with 14.7 months; P = 0.0001), ORR (83.2% versus 55.4%; P < 0.0001), CRR (24.2% versus 2.0%; P < 0.0001), and minimal residual disease rate (7.4% versus 0%; P = 0.0008) compared with chlorambucil. Statistically, significantly more asymptomatic (51.7% versus 7.4%) and symptomatic cytomegalovirus (CMV) infections (15.4% versus 0%) occurred in the patients treated with alemtuzumab. In summary, the currently available evidence suggests an OS, CRR and PFS benefit for alemtuzumab compared with no further therapy, but an increased risk for infections in general, CMV infections and CMV reactivations. The role of alemtuzumab versus rituximab still remains unclear, further trials with longer follow-up and overall survival as primary endpoint are needed to evaluate the effects of both agents compared with each other. Alemtuzumab compared with chlorambucil seems to be favourable in terms of PFS, but a longer follow-up period and trials with overall survival as primary endpoint are needed to determine whether this effect will translate into a survival advantage.
    Cochrane database of systematic reviews (Online) 02/2012; 2(2):CD008078. DOI:10.1002/14651858.CD008078.pub2 · 5.94 Impact Factor

Publication Stats

52 Citations
19.85 Total Impact Points

Institutions

  • 2012–2013
    • MRC Mitochondrial Biology Unit
      Cambridge, England, United Kingdom
    • Mrc Harwell
      Oxford, England, United Kingdom
    • University of Cologne
      • Department of Internal Medicine
      Köln, North Rhine-Westphalia, Germany