Paper plus: Do action plans and regular checkups help children with asthma?

This month, Trish Groves takes you through a cluster randomised trial that offered children regular care and advice on managing their asthma. This type of paper captures a lot of detail, but do not be put off, it is not hard to follow

This month's paper is called "Proactive asthma care in childhood: general practice based randomised controlled trial" (BMJ 2003;327:659-0). To read the paper click here

Why do the study?

Asthma is common in children, but we still do not know the best way of helping children to cope with it. Over the past few years, lots of research studies have shown that adults with long term (chronic) illnesses like asthma and diabetes do better when they are treated actively and shown how to manage their own illnesses. This means that doctors and nurses work more closely with patients-basing treatment on evidence based clinical guidelines, seeing them regularly, responding to their needs, giving them plenty of information, and helping them to behave more healthily. These asthma action plans work for adults, but do they work for children?

In Britain and other countries with similar systems of primary care, most people with asthma, whatever their age, are treated by family doctors and nurses. So it is a good idea to test out asthma action plans in primary care, and that is what the authors of this Australian study did. Firstly, they sent a questionnaire to primary schoolchildren in one part of Australia to find out which children had moderate to severe asthma. Then they offered some of them action plans.

What are asthma action plans?

In this study children with asthma were offered something called the 3+ plan. Like most asthma plans, this was a kind of contract made between doctors and patients. During a routine check up at the family doctor's office or surgery, the doctor asked what each child knew and needed to know about asthma, how the child felt about their asthma, and what help they wanted from the doctor. The doctor or nurse checked each child's inhalers and made sure they knew how to use them. Then, by asking about past and current symptoms, examining the child, and using a spirometer to measure how the lungs were working, the doctor worked out how severe the child's asthma was and how well it was being managed. If it was clear that the current treatment needed to be changed, the doctor explained this and changed the treatment. All of this information made up the child's personalised asthma action plan, which was written down and kept by the doctor and child (or the parents). If the doctor still needed a bit more information, he or she asked the child and family to measure peak flow daily over the next couple of weeks and keep a note of the results in a diary. Then everyone agreed that the child would try to follow the plan and come back for regular check ups.

At the next appointments, around two and four weeks later, the doctor and child discussed the action plan and, perhaps, updated and altered it. If necessary, the doctor might do some further tests, including allergy tests to see if specific things were triggering the asthma. The treatment might need changing again, and a bit more education-of the child, family, or doctor-might happen.

So that was the plan. But, if a whole lot of children were offered plans and got a bit better or worse over the next few weeks and months, nobody would know whether the plan or something else-the weather, air pollution, parental smoking, or something else-had altered their asthma.

RICK RYCROFT/AP

Sydney through the smoke: pollution takes its toll on sufferers of asthma

How could this study show whether asthma action plans made any difference to the children?

The best way to see whether an intervention-a treatment or some other kind of action offered in a study-has any effect is to split your sample into at least two similar groups and offer the intervention to only one of those groups. The rest (called controls) get no intervention or, sometimes, a fake or dummy intervention. When the intervention is a treatment, for instance a drug or physical treatment like physiotherapy, the dummy treatment is called a placebo. Once everyone's in their groups and the intervention has started, the researchers monitor everyone to see what happens. The researchers decide at the beginning how long to monitor for (the length of the follow up period) and what to monitor for (the main outcomes of the trial).

This is called a controlled study, and it is one way of testing if an intervention has worked. But it is not the best way, because getting or not getting the intervention might not be the only important difference between the groups. Perhaps, on average, one group was older, sicker, or less likely to stick with the intervention for social or cultural reasons.

Researchers usually get round this problem by randomising-allocating people at random to one group or another. Randomisation is like flipping a coin-heads you go in one group, tails you go in the other. In trials, though, allocation is usually done in a more sophisticated way, using tables of randomly selected numbers to decide who goes in which group.

What is a cluster randomised trial?

This study of asthma plans for children was a randomised controlled trial with an extra twist-something called a cluster design. This was not just a fancy way of making the trial more complicated. The cluster design made the intervention much more practical, because whole general practices rather than individual children were randomised to the intervention and control groups. The design also allowed the results to be as trustworthy and unbiased as possible.

Say that children were randomised, rather then practices. This means that any one practice could have some children in the intervention group and some in the control group. Imagine two families meeting in their general practitioner's waiting room. They get chatting, and one child's mother says, "Isn't the action plan great? It's the first time we've had time to tell the doctor how scared we are of asthma attacks. And we've worked out how to change the number of puffs according to the peak flow meter-we all feel much more in control." The other child's father says, "But we haven't had an asthma plan-what's it for?" The first family, being friendly and concerned, say they'll happily explain what they've learned so far from the plan.

If everyone did this-and you can see that a lot of families might-the children in the intervention and control groups would end up with similar experiences and the trial's results might become impossible to interpret. And what about the doctors and nurses? Wouldn't they be tempted to try a bit harder to help everyone with asthma, because the mere fact of being in the trial made them more aware of ideal care? Mixing up of the intervention and control groups like this is called contamination. Cluster randomisation makes contamination less likely, though it may not completely avoid mixing of the groups-for instance, the families might meet socially and share their experiences. The cluster design also allows for the fact that patients attending the same practice-and perhaps the same doctor-are likely to experience the same kind of general approach to health care, something that could bias a trial in subtle ways if that practice had patients in the intervention and control groups.

PHANIE AGENCY/REX

Passive smoking may exacerbate asthma

The only other thing you should know about cluster randomisation is that it does affect the numbers in a trial. Firstly, for reasons I will not try to explain here, you need more people in the trial (a bigger sample) to get a statistically significant result-one that is scientifically meaningful. Secondly, a special statistical analysis is needed, which is called, not surprisingly, a cluster analysis.

What did this study show?

A total of 24 general practitioners took part in the study, seeing 174 children with moderate to severe asthma. The intervention and control groups were basically similar to begin with, although the children randomised to the intervention group had, on average, slightly less puff (lower forced expiratory volume) when exposed to cold air in clinical tests.

Eight children were not followed up. At the end of the year of follow up, children in the intervention group had seen their general practitioners about asthma more often than children in the control group, and their consultations were significantly more likely to be ones that actively followed the action plan. Just over a quarter of the children in the intervention group fully completed the 3+ plan, significantly more than the very few in the control group. Another fifth of the children in the intervention group partially completed the 3+ plan. The intervention group had used their written asthma action plans more at 12 months. Overall, five children had to be offered the asthma action plan for one to use it properly (the technical way of saying this is that the number needed to benefit for one additional written asthma action plan was five children).

STOCK MEDICAL/REX

A child using a spacer device to take his medicine

So, just under half of the children in the intervention group followed action plans. But did this make their asthma better? That is what really matters, and the answer is yes, a bit. Compared with children in the control group, those in the intervention group had fewer times over the year when their wheezing was bad enough to stop them speaking, were less reactive to cold air, were more likely to use the right inhalers in the right way and with the right dose of asthma drug, were less likely to use asthma reliever drugs more than four days each week, and tended to end up less often in the emergency department-although this last difference did not reach statistical significance.

Was this a good study?

Yes, it was pretty good. The randomised controlled cluster design was done well and hardly any children dropped out of the study. The study looked at a good mixture of outcomes-checking whether plans were actually followed, whether children's experiences of asthma improved, and whether clinical tests showed less severe asthma. The study method was as close as possible to real clinical practice. The design included an intention to treat analysis, meaning that children allocated to one of the groups were considered to stay in that group throughout the trial, regardless of what happened to them. This means that the results actually represent the worst case scenario: those who did not get better because they did not follow their plans at all were still included as if they had followed them, thus making the intervention look less effective than it probably was in real life. It is disappointing that more than half of the children in the intervention group didn't follow action plans, and a lot of this failure is explained by the fact that their doctors never got round to offering such plans to them. The authors explain that this was due to several reasons-practical problems and to the fact that some of the children actually had rather mild asthma (having been overdiagnosed by the initial questionnaire survey) and did not need intensive treatment and support.

RICHARD GARDNER/REX

An asthma sufferer using a nebuliser

How much does this study matter?

Two American experts in evidence based medicine, David Slawson and Allen Shaughnessy, have come up with the useful concept that a piece of research can be a POEM (patient oriented evidence that matters). This asthma study was a POEM. It used a strong design to study a practical test of improved care for children with asthma.

The idea may not have been entirely new, because we already knew from previous research evidence that action plans work for adults with chronic diseases like asthma. Perhaps common sense could have told us that a similar approach would work in children, but it is good to have that hunch confirmed by reliable research. Of course, a single study cannot have the last word-not even a randomised controlled trial-because another trial in a different sample of children with the same or a slightly different intervention might contradict these findings. But this is a very good place to start. And, given that this intervention did no harm-for instance, by putting loads of families off because it involved effort on their part-and had the admirable aim of making children more in control of their asthma and its treatment, this is an interesting and important study.