International Clinical Trials Day: How many clinical trials are out there?

If you hadn’t noticed, today is international clinical trials day. Celebrating the day, in 1747, when James Lind started his famous trial of treatments for scurvy amongst seafaring men. What was unique about Lind’s approach was the use of experimental controls to compare different interventions, six in total:  all of the seamen involved in the trial received the same diet plus the addition of either cider, elixir vitriol, nutmeg, seawater, vinegar and the eventual cure, deemed to be a luxury at the time, oranges and lemons.  It took only six days for the effective intervention to become apparent.

Six years later Lind published ‘A treatise of scurvy’, which like many of today’s trials was invariably ignored. It was some 20 years later that lemon juice became common-place amongst seamen.

What would have happened if Lind had decided not to publish the results? Keeping the results instead to himself and his own seafaring crew.   Would the lack of publication impacted on the use of a highly effective treatment – or led to delay -for what was a devastating condition at the time?

Yet it currently seems we have not taken to heart the lesson of publishing all results, irrespective of their findings.  It was with this issue in mind – and many more examples that include direct harm to patients - that the AllTrials campaign  was launched earlier this year. It is becoming increasingly clear that all clinical trial results should be published and reported in full.

Indeed, it seems a sizable number of clinical trials have never been published. I am not even sure, if anyone really knows, exactly how many clinical trials there are.

Here is my best estimate, and feel free to criticize, add to or take away from the final number:

1) From a search of PubMed (using the excellent PuBMed Trend database); there are 450,555 RCTs published between 1965 and 2012;

3) EMBASE has been shown to retrieve about 16% more clinical trials than MedLine;

4) About a further 15% of studies are only found through hand searching and other databases;

5) Introduce a fudge factor of +/- 10% to allow for gross over estimates or currently unknown hideouts for unpublished trials .

My best estimate is therefore there are 1,202,080 RCTs (+/-10%) trials of which less than half are currently available for scrutiny.

The AllTrials campaign calls for the “information on what was done and what was found in these trials could be lost forever to doctors and researchers, leading to bad treatment decisions, missed opportunities for good medicine, and trials being repeated.”

All trials past and present should be registered, well at least those in the last 20 years otherwise it will take forever, and the full methods and the results reported.

More than 50,000 people, and 250 organizations, have already signed the petition:

I’m pretty sure James Lind would have signed it.

What evidence is there that pharmaceutical companies withhold clinical trial data

As international clinical trials day approaches (20th May) I’ll be posting a series of articles on AllTrials.

Here is part of my response to the Science and Technology Committee plan to examine the regulation of clinical trials on behalf of the Centre for Evidence-Based Medicine

The evidence for harms for witholding clinical trial data

Whilst modern medicine delivers great benefits to society, its harms due to the withholding of data often prove devastating—with numerous incidents, ranging from thalidomide and antiarrhythmic drugs to Cox II inhibitors. Work from several investigators have highlighted the problems associated with withheld data in which poor regulatory practices have led to direct patient harm, excess costs and delays in the delivery of effective treatments.

Firstly, the extent of underreporting should not be underestimate. A study of 546 drug trials, published between 2000 and 2006 reported only 2/3rds had published their results. Rates of trial publication within 24 months of study completion ranged from 32% among industry-funded trials, to 56% among non-profit or non-federal organization–funded trials.

A further analysis of trials listed on Clinical Trials.Gov, found that of 677 trials completed by 2007 only 46% were published in a peer reviewed biomedical journal, indexed by Medline, within 30 months of trial completion.

Mandatory reporting of trials appears to have made little difference. For example, the overall rate of compliance with the mandatory reporting rate for 2009 trials listed on Clinical Trials.gov within one year following completion, is only 22%.  A further study of clinical trials.gov data between 2009 and 2010 reported that only 52% of 152 trials had associated publications within 2 years after posting. 

Secondly, Six recent case studies are outlined which highlight the problem and the harm caused: (more cases studies can be provided upon request)

Rofecoxib: failure to disclose evidence of harm.

Research by Psaty et al published in JAMA is an example of the importance of withheld data. This case study, by reviewing information provided by the FDA, demonstrated two pivotal published articles of rofecoxib did not include analyses of mortality data, and because of this the studies concluded rofecoxib is “well tolerated.”

In direct contrast, and at the same time as publication, the company’s internal intention-to-treat analyses of pooled data from the same trials identified a significant increase in total mortality.  This equated to an overall mortality of 34 deaths among 1069 rofecoxib patients and 12 deaths among 1078 placebo patients (HR, 2.99; 95% CI, 1.55-5.77).

What is striking about this case is these mortality analyses were neither provided to the US FDA nor made public.

Of more concern was the data submitted to the FDA in a Safety Update Report in July 2001. This data, submitted by the sponsor, used on-treatment analysis methods and reported 29 deaths (2.7%) among 1067 rofecoxib patients and 17 deaths (1.6%) among 1075 placebo patients, thus masking the true mortality difference.

Rosiglitazone: research misconduct and failure to disclose harms

Rosiglitazone is a thiazolidinedione class of drug which was marketed as an addition and/or stand-alone drug to the oral hypoglycaemic agents available to treat patients with uncontrolled type 2 DM.  Annual sales peaked at approximately $2.5bn in 2006; the drug is now withdrawn due to safety issues.

Internal GSK company emails reveal a submitted journal publication, which showed rosiglitazone increased the risk of myocardial infarction, was leaked to GSK. GSKs internal analysis and their company statisticians confirmed the findings and internal company emails demonstrated the company had already come to similar conclusions.

Oseltamivir: Lack of access to full trial programmes

Further to these investigations we have taken a similar approach to Psaty in the analysis of the effects of oseltamivir. [17] Only in response to substantial publicity generated by a joint BMJ-Channel 4 News investigation of oseltamivir, did Roche publicly pledge to make its unpublished full clinical study reports available. [18] The subsequent work has gone on to find a high risk of publication and reporting bias in the trial programme of oseltamivir, which significantly undermines the results published in journals.

Paroxetine: withholding trial data and risk of suicide

GSK was caught withholding clinical trial data showing Paroxetine increased the risk of suicide in young people. The Chief Executive of the MHRA said, “I remain concerned that GSK could and should have reported this information earlier than they did.

Reboxetine: effects of publication bias

Reboxetine was eventually found to be an ineffective and potentially harmful antidepressant after researchers found that 74% of the data from clinical trials had been suppressed during the lead up to the approval of the drug for the acute treatment of severe depression.

Rimonabant 2007: withholding data and delays in withdrawal

In the FDA’s concluded the French manufacturer Sanofi-Aventis failed to demonstrate safety of rimonabant and did not recommend the anti-obesity treatment. The drug had been on sale in Europe for the year previously – The company spent nearly four years withholding data on the risks and benefits of two weight-loss drugs. Acomplia – had to be taken off the market: its harms outweighed its benefits.

There are many more examples that I am sure readers can highlight.

World Health Day: Know your blood pressure

The WHO World Health Day, took place in Geneva on the 3rd of April and the focus was on knowing your blood pressure. Here is a version of the talk I gave at the WHO on the day:

It is increasingly clear that high blood pressure contributes to a substantial number of deaths worldwide, with one in eight of all deaths globally attributable to high blood pressure. Therefore, the recognition and treatment of high blood pressure is a major priority for public health worldwide.

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Because the risk associated with increasing blood pressure is continuous: each 2 mmHg rise in systolic blood pressure is associated with a 7% increased risk of mortality from ischaemic heart disease and a 10% increased risk of mortality from stroke.

Consequently, even small changes in blood pressure can have a profound impact upon the health of a nation. In addition, the majority of events occur in people with mild hypertension, often in those who are economically active. Thus the economic burden for inaction, for not detecting and treating blood pressure, for developing countries will be substantial.

Routine screening and treatment of high blood pressure should therefore become the norm and form a major part of a nations health strategy. As a GP myself, hypertension accounts for a substantial amount of primary care workload; as an example, in the UK it accounts for 12% of all primary care consultations.

With increasing obesity and an ageing population the problem of high blood pressure is set to increase. Therefore managing this tidal wave requires engagement with the wider community.

Given the size and extent of the problem, to improve the wellbeing of individuals and communities, health systems will need to prioritize and target self-care activities.

Self-care is the ability of individuals, families and communities to promote health, prevent disease and maintain wellbeing.

We have been working for the last two years, with the WHO on a Self care in NCDs guideline which is due for publication imminently. Self-care can involve a number of lifestyle changes that can be extremely effective in reducing high blood pressure: eating a healthy diet
, reducing salt intake (to less than 5g daily),exercising regularly
, stopping smoking
 and reducing alcohol consumption.

However, in many cases medication must be used, in conjunction with lifestyle changes.

Community interventions will need to be delivered beyond health care institutions, targeted to the detection and ongoing management of blood pressure, aiming to work closely with primary health care. Such programs should have sufficient flexibility to ensure they are locally and contextually appropriate.

Structured training for community workers to aid the detection and ongoing management of hypertension and, education and informing the wider public are a priority for healthcare systems.

Finally, once treatment has been initiated we need to think about how individuals can be empowered to effectively manage their own care. Self-monitoring of blood pressure has evidence for its effectiveness, particularly where the affordability of the technology has been established. Also strategies to improve adherence to medications should form part of the overall self-care pathway for hypertension.

In developing a strategy to tackle high blood pressure there are two important issues to recognize:  first, that hypertension often coexists with other diseases and health systems should avoid vertical systems; second, there is a need to continually develop the evidence base, using a network of epidemiology centres to identify and evaluate effective programs targeted at blood pressure care, sharing best practice. It is important that interventions need to be based on evidence- resources are scarce; (expert patient programs have wasted money in the past)

We can prevent 80% of cardiovascular with what we already know; we now need action to implement effective change to improve blood pressure care and expediency to further develop the evidence base for what is effective and what is not.

 

Telehealth: a tale of two headlines

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In November 2012, research funded by the Department of health reported a 20% reduction in emergency admissions.

It was widely reported that health technologies were set to improve the lives of people with long term conditions. Also with reductions  in A&E visits and  a substantial, 40% reduction in mortality.

Health Secretary at the time, Jeremy Hunt said, “Technology can help people manage their condition at home, free up a lot of time and save the NHS money. In a world where technology increasingly helps us manage our social and professional lives, it seems logical that it should also help people manage their health.”

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But and its a big but, last week the BMJ reported the peer reviewed results of the effects of the same study on quality of life and psychological outcomes for the very same whole system demonstrator: reporting it was not effective when compared with usual care.

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In June 2012 – the mortality findings were reported in the in the BMJ – showing  Telehealth is associated with lower mortality and emergency admission rates.

Now unless I missed something, and correct me if I have, these are the same studies; but they come to almost exact opposite conclusions. Can someone tie the ends together and let me know what is going on: it seems Jeremy Hunt and myself are pretty confused.

Observational data for Tamiflu effects just doesn’t add up

The reason no one sticks  to the results of randomized trials is that they believe the dramatic effects observed in observational studies.

It is important to note the World Health Organization approved the use of Oseltamivir on the essential medicines list on the basis of observational data.

What the WHO did was fund a review of observational studies, you can get it here, the results of which were presented to an expert committee, in Ghana, in March 2011.

The review reported a large effect on mortality. Yet, get this, the mortality result was based on only three studies. Three studies and you are on the essential medicines list, that can’t be right?

More importantly, does anyone actually read these studies?

These three studies were done in hospitalized patients; but none actually described the reasons for administering oseltamivir to patients.

One of these studies, undertaken in Thailand,  was a retrospective review of medical records. Even the authors called for caution in interpreting their results, ‘our small, retrospective, observational study has limitations with respect to establishing causality.’

The reported effect size is truly large: the authors report that 310 of 423 non-fatal cases (73%) took oseltamivir whereas 5 of 22 fatal cases (23%) only took the drug: Crude Odds ratio was 0.11. Note they only reviewed 22 fatal cases (you could have picked any 22 cases) and, only 29% of the medical records for the non-fatal cases were actually reviewed.

The second study was also a retrospective review of clinical data. Medical data was obtained for 67 (72%) of 93 cases diagnosed with human influenza A (H5N1) in Vietnam. Oseltamivir was administered in 55 (82%) of the 67 cases. But after adjustment for age the effect of tamiflu was not statistically significant.

The third study, funded by the manufacturer undertaken in adults in Toronto requiring hospitalization, noted a number of limitations .  Only 63% of eligible patients were tested for influenza, data collection was by chart review, which limited the number of risk factors that might have been considered.

If you see a large effect in observational effects it is more likely to be due to poor quality evidence and systematic biases, which the review points out clearly in their limitations.

The very fact that the observational studies were retrospective, done after the event, renders their results invalid. Evidence–Based Medicine is not difficult, it is just time consuming, as it requires reading the research. So, exactly  why did this treatment get on the essential medicines list?