Intended for healthcare professionals


Case reports of suspected adverse drug reactions: Case reports were dismissed too quickly

BMJ 2006; 332 doi: (Published 23 February 2006) Cite this as: BMJ 2006;332:488

Funding for hypothesis-testing studies

I have followed with interest the correspondence following
publication of the Loke et al paper regarding case reports of adverse drug
reactions (1). Although this paper concluded that case reports in
pharmacovigilance have limited value, it has subsequently been agreed that
case reports/series are valuable as hypothesis-generating papers and that
clinicians and patients benefit from these reports. I would add that the
number of follow-up studies is only one outcome by which to judge the
value of case reports/series, but other outcomes may be more difficult to

Whilst case reports are valuable in pharmacovigilance, there is no
doubt that hypothesis testing studies are necessary and I agree with JP
Vandenbroucke that a more consistent scheme is needed (2). An important
question is where will funding for such studies come from? Pharmaceutical
companies may have little incentive to further investigate adverse
reactions and if funding is provided there may be conflicting interests.
For different reasons, governments may also be reluctant to fund
pharmacoepidemiology studies (3).

Here in New Zealand, the government-funded Intensive Medicines
Monitoring Programme (IMMP) performs hypothesis-testing studies which
further investigate adverse drug reactions, including calculating
incidence and identifying patients at risk (4). The IMMP was established
in 1977 when it was recognised that spontaneous reports were insufficient
to detect and fully evaluate adverse drug reactions. In its almost 30-year
history, the IMMP has performed many valuable studies and is
internationally respected (3) yet its future remains uncertain. At the
time of writing (March 2006) none of the IMMP staff has a contract beyond
30 June 2006. It is still not known how the IMMP will contribute to the
new Australia New Zealand Therapeutic Products Agency (5). In the
meantime, important pharmacoepidemiology studies are at risk of not being
completed, with loss of valuable data contributed over many years by
patients and doctors throughout New Zealand. I give these details to make
this point: the agreement that hypothesis-testing studies are required as
a component of pharmacovigilance must be backed by a commitment to
adequately fund such work.

1. Loke YK, Price D, Derry S, Aronson JK. Case reports of suspected
adverse drug reactions--systematic literature survey of follow-up. BMJ
2006; 332:335-339. (11 February)

2. Vandenbroucke JP. Case reports of suspected adverse reactions
(letter). BMJ 2006 332:488 (25 February)

3. Herxheimer A. Open letter to Annette King, Minister of Health New
Zealand (letter). BMJ 2004; 329:51 (3 July 2004)

4. Harrison-Woolrych M, Coulter DM. PEM in New Zealand. In:
Pharmacovigilance (second edition). Editors Mann R, Andrews E.
Chichester, John Wiley and Sons, England 2006, in press.

5. Australia New Zealand Therapeutic Products Authority website
available at:

Competing interests:
I am the Director of the New Zealand IMMP

Competing interests: No competing interests

01 March 2006
Mira Harrison-Woolrych
Director, Intensive Medicines Monitoring Programme
University of Otago, Dunedin, New Zealand