Increased transparency was required when reporting imputation of primary outcome data in clinical trials

OBJECTIVE

To explore the transparency of reporting primary outcome data within randomised controlled trials (RCTs) in the presence of missing data.

STUDY DESIGN

/ Setting: A cohort examination of RCTs published in the four major medical journals (NEJM, JAMA, BMJ, Lancet) in 2013 and the first quarter of 2018. Data was extracted on reporting quality, the number of randomised participants and the number of participants included within the primary outcome analysis with observed or imputed data.

RESULTS

91/159 (57%) of the studies analysed from 2013 and 19/46 (41%) from 2018 included imputed data within the primary outcome analysis. Of these, only 13/91 (14%) studies from 2013 and 1/19 (5%) studies from 2018 explicitly reported the number of imputed values in the CONSORT diagram. Results tables included levels of imputed data in 12/91 (13%) studies in 2013 and 4/19 (21%) in 2018. Consequently, identification of imputed data was a time-consuming task requiring extensive cross-referencing of all manuscript elements.

CONCLUSION

Imputed primary outcome data is poorly reported. Participant flow diagrams frequently reported participant status which does not necessarily correlate to availability of data. We recommended that the number of imputed values are explicitly reported within CONSORT flow diagrams to increase transparency.

A web-based, peer-supported self-management intervention to reduce distress in relatives of people with psychosis or bipolar disorder: the REACT RCT

BACKGROUND

Relatives caring for people with severe mental health problems find information and emotional support hard to access. Online support for self-management offers a potential solution.

OBJECTIVE

The objective was to determine the clinical effectiveness and cost-effectiveness of an online supported self-management tool for relatives: the Relatives' Education And Coping Toolkit (REACT).

DESIGN AND SETTING

This was a primarily online (UK), single-blind, randomised controlled trial, comparing REACT plus a resource directory and treatment as usual with the resource directory and treatment as usual only, by measuring user distress and other well-being measures at baseline and at 12 and 24 weeks.

PARTICIPANTS

A total of 800 relatives of people with severe mental health problems across the UK took part; relatives who were aged ≥ 16 years, were experiencing high levels of distress, had access to the internet and were actively seeking help were recruited.

INTERVENTION

REACT comprised 12 psychoeducation modules, peer support through a group forum, confidential messaging and a comprehensive resource directory of national support. Trained relatives moderated the forum and responded to messages.

MAIN OUTCOME MEASURE

The main outcome was the level of participants' distress, as measured by the General Health Questionnaire-28 items.

RESULTS

Various online and offline strategies, including social media, directed potential participants to the website. Participants were randomised to one of two arms: REACT plus the resource directory (n = 399) or the resource directory only (n = 401). Retention at 24 weeks was 75% (REACT arm, n = 292; resource directory-only arm, n = 307). The mean scores for the General Health Questionnaire-28 items reduced substantially across both arms over 24 weeks, from 40.2 (standard deviation 14.3) to 30.5 (standard deviation 15.6), with no significant difference between arms (mean difference -1.39, 95% confidence interval -3.60 to 0.83; p = 0.22). At 12 weeks, the General Health Questionnaire-28 items scores were lower in the REACT arm than in the resource directory-only arm (-2.08, 95% confidence interval -4.14 to -0.03; p = 0.027), but this finding is likely to be of limited clinical significance. Accounting for missing data, which were associated with higher distress in the REACT arm (0.33, 95% confidence interval -0.27 to 0.93; p = 0.279), in a longitudinal model, there was no significant difference between arms over 24 weeks (-0.56, 95% confidence interval -2.34 to 1.22; p = 0.51). REACT cost £142.95 per participant to design and deliver (£62.27 for delivery only), compared with £0.84 for the resource directory only. A health economic analysis of NHS, health and Personal Social Services outcomes found that REACT has higher costs (£286.77), slightly better General Health Questionnaire-28 items scores (incremental General Health Questionnaire-28 items score adjusted for baseline, age and gender: -1.152, 95% confidence interval -3.370 to 1.065) and slightly lower quality-adjusted life-year gains than the resource directory only; none of these differences was statistically significant. The median time spent online was 50.8 minutes (interquartile range 12.4-172.1 minutes) for REACT, with no significant association with outcome. Participants reported finding REACT a safe, confidential environment (96%) and reported feeling supported by the forum (89%) and the REACT supporters (86%). No serious adverse events were reported.

LIMITATIONS

The sample comprised predominantly white British females, 25% of participants were lost to follow-up and dropout in the REACT arm was not random.

CONCLUSIONS

An online self-management support toolkit with a moderated group forum is acceptable to relatives and, compared with face-to-face programmes, offers inexpensive, safe delivery of National Institute for Health and Care Excellence-recommended support to engage relatives as peers in care delivery. However, currently, REACT plus the resource directory is no more effective at reducing relatives' distress than the resource directory only.

FUTURE WORK

Further research in improving the effectiveness of online carer support interventions is required.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN72019945.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 32. See the NIHR Journals Library website for further project information.

Planning for success: overcoming challenges to recruitment and conduct of an open-label emergency department-led paediatric trial

BACKGROUND

Key challenges to the successful conduct of The Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children (EcLiPSE) trial were identified at the pre-trial stage. These included practitioner anxieties about conducting research without prior consent (RWPC), inexperience in conducting an ED-led trial and use of a medication that was not usual ED practice. As part of an embedded study, we explored parent and practitioner experiences of recruitment, RWPC and conduct of the trial to inform the design and conduct of future ED-led trials.

METHODS

A mixed-methods study within a trial involving (1) questionnaires and interviews with parents of randomised children, (2) interviews and focus groups with EcLiPSE practitioners and (3) audio-recorded trial discussions. We analysed data using thematic analysis and descriptive statistics as appropriate.

RESULTS

A total of 143 parents (93 mothers, 39 fathers, 11 missing information) of randomised children completed a questionnaire and 30 (25 mothers, 5 fathers) were interviewed. We analysed 76 recorded trial recruitment discussions. Ten practitioners (4 medical, 6 nursing) were interviewed, 36 (16 medical, 20 nursing) participated in one of six focus groups. Challenges to the success of the trial were addressed by having a clinically relevant research question, pragmatic trial design, parent and practitioner support for EcLiPSE recruitment and research without prior consent processes, and practitioner motivation and strong leadership. Lack of leadership negatively affected practitioner engagement and recruitment. EcLiPSE completed on time, achieving its required sample size target.

CONCLUSIONS

Successful trial recruitment and conduct in a challenging ED-led trial was driven by trial design, recruitment experience, teamwork and leadership. Our study provides valuable insight from parents and practitioners to inform the design and conduct of future trials in this setting.

Antimicrobial-impregnated central venous catheters for preventing neonatal bloodstream infection: the PREVAIL RCT

BACKGROUND

Clinical trials show that antimicrobial-impregnated central venous catheters reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is insufficient evidence for use in newborn babies.

OBJECTIVES

The objectives were (1) to determine clinical effectiveness by conducting a randomised controlled trial comparing antimicrobial-impregnated peripherally inserted central venous catheters with standard peripherally inserted central venous catheters for reducing bloodstream or cerebrospinal fluid infections (referred to as bloodstream infections); (2) to conduct an economic evaluation of the costs, cost-effectiveness and value of conducting additional research; and (3) to conduct a generalisability analysis of trial findings to neonatal care in the NHS.

DESIGN

Three separate studies were undertaken, each addressing one of the three objectives. (1) This was a multicentre, open-label, pragmatic randomised controlled trial; (2) an analysis was undertaken of hospital care costs, lifetime cost-effectiveness and value of information from an NHS perspective; and (3) this was a retrospective cohort study of bloodstream infection rates in neonatal units in England.

SETTING

The randomised controlled trial was conducted in 18 neonatal intensive care units in England.

PARTICIPANTS

Participants were babies who required a peripherally inserted central venous catheter (of 1 French gauge in size).

INTERVENTIONS

The interventions were an antimicrobial-impregnated peripherally inserted central venous catheter (coated with rifampicin-miconazole) or a standard peripherally inserted central venous catheter, allocated randomly (1 : 1) using web randomisation.

MAIN OUTCOME MEASURE

Study 1 - time to first bloodstream infection, sampled between 24 hours after randomisation and 48 hours after peripherally inserted central venous catheter removal. Study 2 - cost-effectiveness of the antimicrobial-impregnated peripherally inserted central venous catheter compared with the standard peripherally inserted central venous catheters. Study 3 - risk-adjusted bloodstream rates in the trial compared with those in neonatal units in England. For study 3, the data used were as follows: (1) case report forms and linked death registrations; (2) case report forms and linked death registrations linked to administrative health records with 6-month follow-up; and (3) neonatal health records linked to infection surveillance data.

RESULTS

Study 1, clinical effectiveness - 861 babies were randomised (antimicrobial-impregnated peripherally inserted central venous catheter, n = 430; standard peripherally inserted central venous catheter, n = 431). Bloodstream infections occurred in 46 babies (10.7%) randomised to antimicrobial-impregnated peripherally inserted central venous catheters and in 44 (10.2%) babies randomised to standard peripherally inserted central venous catheters. No difference in time to bloodstream infection was detected (hazard ratio 1.11, 95% confidence interval 0.73 to 1.67; p = 0.63). Secondary outcomes of rifampicin resistance in positive blood/cerebrospinal fluid cultures, mortality, clinical outcomes at neonatal unit discharge and time to peripherally inserted central venous catheter removal were similar in both groups. Rifampicin resistance in positive peripherally inserted central venous catheter tip cultures was higher in the antimicrobial-impregnated peripherally inserted central venous catheter group (relative risk 3.51, 95% confidence interval 1.16 to 10.57; p = 0.02) than in the standard peripherally inserted central venous catheter group. Adverse events were similar in both groups. Study 2, economic evaluation - the mean cost of babies' hospital care was £83,473. Antimicrobial-impregnated peripherally inserted central venous catheters were not cost-effective. Given the increased price, compared with standard peripherally inserted central venous catheters, the minimum reduction in risk of bloodstream infection for antimicrobial-impregnated peripherally inserted central venous catheters to be cost-effective was 3% and 15% for babies born at 23-27 and 28-32 weeks' gestation, respectively. Study 3, generalisability analysis - risk-adjusted bloodstream infection rates per 1000 peripherally inserted central venous catheter days were similar among babies in the trial and in all neonatal units. Of all bloodstream infections in babies receiving intensive or high-dependency care in neonatal units, 46% occurred during peripherally inserted central venous catheter days.

LIMITATIONS

The trial was open label as antimicrobial-impregnated and standard peripherally inserted central venous catheters are different colours. There was insufficient power to determine differences in rifampicin resistance.

CONCLUSIONS

No evidence of benefit or harm was found of peripherally inserted central venous catheters impregnated with rifampicin-miconazole during neonatal care. Interventions with small effects on bloodstream infections could be cost-effective over a child's life course. Findings were generalisable to neonatal units in England. Future research should focus on other types of antimicrobial impregnation of peripherally inserted central venous catheters and alternative approaches for preventing bloodstream infections in neonatal care.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN81931394.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 57. See the NIHR Journals Library website for further project information.

Duration of initial antibiotic course is associated with recurrent relapse in protracted bacterial bronchitis

Protracted bacterial bronchitis (PBB) is the leading cause of chronic wet cough in young children from developed countries. Despite its high prevalence there is a paucity of evidence to inform the optimal duration of treatment leading to variation in practice. Relapse of chronic cough is common and recurrent PBB (>3 episodes in 12 months) is associated with a future diagnosis of bronchiectasis. We investigated the factors associated with any relapse (≥1 episode in 12 months) and recurrent PBB in 66 children. No factor was significantly associated with any relapse. Duration of initial antibiotic treatment was the only factor significantly associated with recurrent PBB. Those who received antibiotics for 6 weeks antibiotics were less likely to develop recurrent PBB than those who received for 2 weeks (p=0.046). This is the first study to show an association between duration of initial antibiotic course and therefore future bronchiectasis. Prospective studies are needed to investigate this association.

Adalimumab in combination with methotrexate for refractory uveitis associated with juvenile idiopathic arthritis: a RCT

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) are at risk of uveitis. The role of adalimumab (Humira^®; AbbVie Inc., Ludwigshafen, Germany) in the management of uveitis in children needs to be determined.

OBJECTIVE

To compare the efficacy, safety and cost-effectiveness of adalimumab in combination with methotrexate (MTX) versus placebo with MTX alone, with regard to controlling disease activity in refractory uveitis associated with JIA.

DESIGN

This was a randomised (applying a ratio of 2 : 1 in favour of adalimumab), double-blind, placebo-controlled, multicentre parallel-group trial with an integrated economic evaluation. A central web-based system used computer-generated tables to allocate treatments. A cost-utility analysis based on visual acuity was conducted and a 10-year extrapolation by Markov modelling was also carried out.

SETTING

The setting was tertiary care centres throughout the UK.

PARTICIPANTS

Patients aged 2-18 years inclusive, with persistently active JIA-associated uveitis (despite optimised MTX treatment for at least 12 weeks).

INTERVENTIONS

All participants received a stable dose of MTX and either adalimumab (20 mg/0.8 ml for patients weighing < 30 kg or 40 mg/0.8 ml for patients weighing ≥ 30 kg by subcutaneous injection every 2 weeks based on body weight) or a placebo (0.8 ml as appropriate according to body weight by subcutaneous injection every 2 weeks) for up to 18 months. A follow-up appointment was arranged at 6 months.

MAIN OUTCOME MEASURES

Primary outcome - time to treatment failure [multicomponent score as defined by set criteria based on the Standardisation of Uveitis Nomenclature (SUN) criteria]. Economic outcome - incremental cost per quality-adjusted life-year (QALY) gained from the perspective of the NHS in England and Personal Social Services providers. Full details of secondary outcomes are provided in the study protocol.

RESULTS

A total of 90 participants were randomised (adalimumab, n = 60; placebo, n = 30). There were 14 (23%) treatment failures in the adalimumab group and 17 (57%) in the placebo group. The analysis of the data from the double-blind phase of the trial showed that the hazard risk (HR) of treatment failure was significantly reduced, by 75%, for participants in the adalimumab group (HR 0.25, 95% confidence interval 0.12 to 0.51; p < 0.0001 from log-rank test). The cost-effectiveness of adalimumab plus MTX was £129,025 per QALY gained. Adalimumab-treated participants had a much higher incidence of adverse and serious adverse events.

CONCLUSIONS

Adalimumab in combination with MTX is safe and effective in the management of JIA-associated uveitis. However, the likelihood of cost-effectiveness is < 1% at the £30,000-per-QALY threshold.

FUTURE WORK

A clinical trial is required to define the most effective time to stop therapy. Prognostic biomarkers of early and complete response should also be identified.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10065623 and European Clinical Trials Database number 2010-021141-41.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 15. See the NIHR Journals Library website for further project information. This trial was also funded by Arthritis Research UK (grant reference number 19612). Two strengths of adalimumab (20 mg/0.8 ml and 40 mg/0.8 ml) and a matching placebo were manufactured by AbbVie Inc. (the Marketing Authorisation holder) and supplied in bulk to the contracted distributor (Sharp Clinical Services, Crickhowell, UK) for distribution to trial centres.

Seven-step framework to enhance practitioner explanations and parental understandings of research without prior consent in paediatric emergency and critical care trials

Background

Alternatives to prospective informed consent enable the conduct of paediatric emergency and critical care trials. Research without prior consent (RWPC) involves practitioners approaching parents after an intervention has been given and seeking consent for their child to continue in the trial. As part of an embedded study in the ‘Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children’ (EcLiPSE) trial, we explored how practitioners described the trial and RWPC during recruitment discussions, and how well this information was understood by parents. We aimed to develop a framework to assist trial conversations in future paediatric emergency and critical care trials using RWPC.

Methods

Qualitative methods embedded within the EcLiPSE trial processes, including audiorecorded practitioner–parent trial discussions and telephone interviews with parents. We analysed data using thematic analysis, drawing on the Realpe et al (2016) model for recruitment to trials.

Results

We analysed 76 recorded trial discussions and conducted 30 parent telephone interviews. For 19 parents, we had recorded trial discussion and interview data, which were matched for analysis. Parental understanding of the EcLiPSE trial was enhanced when practitioners: provided a comprehensive description of trial aims; explained the reasons for RWPC; discussed uncertainty about which intervention was best; provided a balanced description of trial intervention; provided a clear explanation about randomisation and provided an opportunity for questions. We present a seven-step framework to assist recruitment practice in trials involving RWPC.

Conclusion

This study provides a framework to enhance recruitment practice and parental understanding in paediatric emergency and critical care trials involving RWPC. Further testing of this framework is required.

Methodological Challenges in Web-Based Trials: Update and Insights From the Relatives Education and Coping Toolkit Trial

RR2-10.1136/bmjopen-2017-016965.

Clinical effectiveness of a web-based peer-supported self-management intervention for relatives of people with psychosis or bipolar (REACT): online, observer-blind, randomised controlled superiority trial

BACKGROUND

The Relatives Education And Coping Toolkit (REACT) is an online supported self-management toolkit for relatives of people with psychosis or bipolar designed to improve access to NICE recommended information and emotional support.

AIMS

Our aim was to determine clinical and cost-effectiveness of REACT including a Resource Directory (RD), versus RD-only.

METHODS

A primarily online, observer-blind randomised controlled trial comparing REACT (including RD) with RD only (registration ISRCTN72019945). Participants were UK relatives aged > = 16, with high distress (assessed using the GHQ-28), and actively help-seeking, individually randomised, and assessed online. Primary outcome was relatives' distress (GHQ-28) at 24 weeks. Secondary outcomes were wellbeing, support, costs and user feedback.

RESULTS

We recruited 800 relatives (REACT = 399; RD only = 401) with high distress at baseline (GHQ-28 REACT mean 40.3, SD 14.6; RD only mean 40.0, SD 14.0). Median time spent online on REACT was 50.8 min (IQR 12.4-172.1) versus 0.5 min (IQR 0-1.6) on RD only. Retention to primary follow-up (24 weeks) was 75% (REACT n = 292 (73.2%); RD-only n = 307 (76.6%)). Distress decreased in both groups by 24 weeks, with no significant difference between the two groups (- 1.39, 95% CI -3.60, 0.83, p = 0.22). Estimated cost of delivering REACT was £62.27 per person and users reported finding it safe, acceptable and convenient. There were no adverse events or reported side effects.

CONCLUSIONS

REACT is an inexpensive, acceptable, and safe way to deliver NICE-recommended support for relatives. However, for highly distressed relatives it is no more effective in reducing distress (GHQ-28) than a comprehensive online resource directory.

TRIAL REGISTRATION

ISRCTN72019945 prospectively registered 19/11/2015.

Antimicrobial-impregnated central venous catheters for prevention of neonatal bloodstream infection (PREVAIL): an open-label, parallel-group, pragmatic, randomised controlled trial

BACKGROUND

Bloodstream infection is associated with high mortality and serious morbidity in preterm babies. Evidence from clinical trials shows that antimicrobial-impregnated central venous catheters (CVCs) reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is a paucity of similar evidence for babies receiving neonatal intensive care.

METHODS

This open-label, parallel-group, pragmatic, randomised controlled trial was done in 18 neonatal intensive care units in England. Newborn babies who needed a peripherally inserted CVC (PICC) were allocated randomly (1:1) to receive either a PICC impregnated with miconazole and rifampicin or a standard (non-antimicrobial-impregnated) PICC. Random allocation was done with a web-based program, which was centrally controlled to ensure allocation concealment. Randomisation sequences were computer-generated in random blocks of two and four, and stratified by site. Masking of clinicians to PICC allocation was impractical because rifampicin caused brown staining of the antimicrobial-impregnated PICC. However, participant inclusion in analyses and occurrence of outcome events were determined following an analysis plan that was specified before individuals saw the unblinded data. The primary outcome was the time from random allocation to first microbiologically confirmed bloodstream or cerebrospinal fluid (CSF) infection between 24 h after randomisation and 48 h after PICC removal or death. We analysed outcome data according to the intention-to-treat principle. We excluded babies for whom a PICC was not inserted from safety analyses, as these analyses were done with groups defined by the PICC used. This trial is registered with ISRCTN, number 81931394.

FINDINGS

Between Aug 12, 2015, and Jan 11, 2017, we randomly assigned 861 babies (754 [88%] born before 32 weeks of gestation) to receive an antimicrobial-impregnated PICC (430 babies) or standard PICC (431 babies). The median time to PICC removal was 8·20 days (IQR 4·77-12·13) in the antimicrobial-impregnated PICC group versus 7·86 days (5·00-12·53) days in the standard PICC group (hazard ratio [HR] 1·03, 95% CI 0·89-1·18, p=0·73), with 46 (11%) of 430 babies versus 44 (10%) of 431 babies having a microbiologically confirmed bloodstream or CSF infection. The time from random allocation to first bloodstream or CSF infection was similar between the two groups (HR 1·11, 95% CI 0·73-1·67, p=0·63). Secondary outcomes relating to infection, rifampicin resistance in positive blood or CSF cultures, mortality, clinical outcomes at neonatal unit discharge, and time to PICC removal were similar between the two groups, although rifampicin resistance in positive cultures of PICC tips was higher in the antimicrobial-impregnated PICC group (relative risk 3·51, 95% CI 1·16-10·57, p=0·018). 60 adverse events were reported from 49 (13%) patients in the antimicrobial-impregnated PICC group and 50 events from 45 (10%) babies in the standard PICC group.

INTERPRETATION

We found no evidence of benefit or harm associated with miconazole and rifampicin-impregnated PICCs compared with standard PICCs for newborn babies. Future research should focus on other types of antimicrobial impregnation of PICCs and alternative approaches for preventing infection.

FUNDING

UK National Institute for Health Research Health Technology Assessment programme.

Enhancing practitioners' confidence in recruitment and consent in the EcLiPSE trial: a mixed-method evaluation of site training - a Paediatric Emergency Research in the United Kingdom and Ireland (PERUKI) study

Background

EcLiPSE (Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children) is a randomised controlled trial (RCT) in the United Kingdom. Challenges to success include the need to immediately administer an intervention without informed consent and changes in staffing during trial conduct, mainly due to physician rotations. Using literature on parents’ perspectives and research without prior consent (RWPC) guidance, we developed an interactive training package (including videos, simulation and question and answer sessions) and evaluated its dissemination and impact upon on practitioners’ confidence in recruitment and consent.

Methods

Questionnaires were administered before and immediately after training followed by telephone interviews (mean 11 months later), focus groups (mean 14 months later) and an online questionnaire (8 months before trial closure).

Results

One hundred and twenty-five practitioners from 26/30 (87%) participating hospitals completed a questionnaire before and after training. We conducted 10 interviews and six focus groups (comprising 36 practitioners); 199 practitioners working in all recruiting hospitals completed the online questionnaire. Before training, practitioners were concerned about recruitment and consent. Confidence increased after training for explaining (all scale 0–5, 95% CIs above 0 and p values < 0.05): the study (66% improved mean score before 3.28 and after 4.52), randomisation (47% improvement, 3.86 to 4.63), RWPC (72% improvement, 2.98 to 4.39), and addressing parents’ objections to randomisation (51% improvement, 3.37 to 4.25). Practitioners rated highly the content and clarity of the training, which was successfully disseminated. Some concerns about staff availability for training and consent discussions remained.

Conclusions

Training improved practitioners’ confidence in recruitment and RWPC. Our findings highlight the value of using parents’ perspectives to inform training and to engage practitioners in trials that are at high risk of being too challenging to conduct.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3273-z) contains supplementary material, which is available to authorized users.

Inducers of interferon inhibit the mitotic response of liver cells to partial hepatectomy

Partially hepatectomized mice were injected with inducers of interferon, and the mitotic activity of liver cells was measured. The inducers were polyriboinosinic.polyribocytidylic acid, poly(I.C), Newcastle disease virus, and statolon. Each inhibited the mitosis of liver cells. Poly(I.C) was effective in doses as low as 1 mug per mouse. Polyriboinosinic acid, poly(I), had no inhibitory effect. These results extend the spectrum of action of inducers of interferon to inhibition of mitotic division of an aneoplastic, nonaneuploid mammalian cell.