Analysis of adherence to peak flow monitoring when recording of data is electronic

The article by Reddel et al (BMJ 2002;324:146-147) raises some
interesting and important points regarding peak flow measurement in asthma
care. The authors found very high levels of adherence to a peak flow
monitoring regimen and attribute this to the use of electronic devices.

However, is this the entire answer? Reddel et al note that the
electronic peak flow monitoring took place in the context of regular
(eight weekly) visits and titration of medications according to peak flow
data. The authors themselves comment that “the context in which monitoring
is undertaken may influence adherence” and further note the importance of
the perceived usefulness of peak flow data in ensuring that patients use
these devices. Was it, then, the design of the intervention - with regular
follow-up, clear self-management plans and clear linking of peak flow
readings with medication doses - rather than the electronic measuring
devices per se which accounted for the high levels of adherence? In the
absence of a comparator group who used only “traditional” devices, it is
difficult to conclude confidently that the electronic nature, or any other
feature, of the devices themselves was the reason for the laudably high
levels of adherence achieved.

Data from our recently completed study of asthma patients’ views
regarding treatment decision-making would tend to support the conclusion
that it is the perceived usefulness of the information provided which
determines whether peak flow meters are used. In our sample of 230
patients, drawn from both primary and secondary care in the UK and with a
range of asthma severity, 110 (47.8%) reported having a peak flow meter.
Of these 110, only 32 (29.0%) stated that they would use peak flow
readings to adjust medications, with 73 (66.4%) stating that they would
not do so. By contrast, 180 of the 230 patients reported using symptoms to
guide their medication usage.

The conclusion that we draw from these data and, we believe, the
important message from Reddel et al’s paper is this: only if the
information provided by peak flow meters – whether electronic or not – is
relevant and part of a fully explained self-management plan will patients
perhaps use these devices.