Study adds little to tonsil surgery debate

The NHS "should remove more tonsils," reports The Daily Telegraph, describing how we should "return closer to the 1950s culture of whipping tonsils out in spite of the cost."

It's tempting to take this news at face value, given that it is based on a study that found that adults with recurrent severe sore throats had fewer sore throats if they had their tonsils removed.

However, this small short-term Finnish study adds little weighty evidence to the ongoing debate about whether surgery is the best option for treating this problem.

The study found that surgery did reduce the number of people visiting their doctor with a sore throat within five months: 4% of patients who had their tonsils removed saw their GP, compared with 43% who had not yet had surgery.

The researchers therefore concluded that removing tonsils may be effective at preventing severe sore throats. However, there was no difference in the number of people who had a severe sore throat after five months.

The Telegraph's story failed to highlight potential problems with the research, or point out that it would not be the basis for a substantial change in medical practices in this country.

Despite this slightly wayward reporting, The Telegraph does well to reignite the debate about whether tonsillectomies should be performed more often. Medical and surgical practices that have fallen out of favour should always be re-evaluated using the most up-to-date research evidence.

However, any change in medical practices will be the result of the progressive accumulation of larger, more robust studies showing more conclusive results than this current research.

Where did the story come from?

The study was carried out by researchers from Oulu University Hospital in Finland. No funding source was explicitly stated, but no competing interests were declared.

It was published in the peer-reviewed Canadian Medical Association Journal.

There is limited evidence about the benefits of tonsillectomy in adult patients. This research wanted to look at the short-term effectiveness of tonsillectomy for patients with recurring pharyngitis.

The media reporting was generally accurate, but overstated the importance of this research. It failed to highlight many of the important limitations of this study, including its size and whether its findings can be applied to English patients.

What kind of research was this?

This study was a small randomised control trial that wanted to see if tonsillectomies were an effective way of reducing the number of episodes of severe pharyngitis among adult patients with recurrent pharyngitis of any origin.

Pharyngitis is a sore throat usually caused by a viral or bacterial infection. It is common in children and teenagers as they haven't yet built up immunity for the common viruses and bacteria that cause sore throats.

Most people are familiar with the notion that taking out tonsils will remedy tonsillitis (inflamed tonsils). It is important to note, however, that this study looked at whether removing the tonsils was effective for reducing the number of episodes of inflammation of the throat in general (pharyngitis).

What did the research involve?

The researchers recruited 86 patients referred from a specialist ear, nose and throat centre in Oulu, Finland. These patients were referred for tonsillectomy because of recurrent pharyngitis. The participants were recruited from 260 eligible patients referred to the centre between 2007 and 2010.

To be included in the study, patients had to have experienced three or more episodes of pharyngitis within the previous 12 months. These episodes had to be 'disabling': they had to prevent normal functioning, be severe enough for the patient to seek medical attention, and the tonsils had to be thought to be involved in each episode. Children under the age of 13 were excluded, as were those with chronic tonsillitis.

Participants were randomly assigned to either:

be placed on a waiting list (the control) for tonsillectomy to have surgery in five to six months (40 people), or
undergo surgery as soon as possible (46 people)

Patients were told to visit the study physician or their general practitioner whenever they had short-term symptoms suggestive of pharyngitis. Patients were also told that it was important to seek medical advice for their symptoms during the trial exactly as they had done before.

Both patient groups were followed-up five months after randomisation. During this time, they kept study notebooks to remind them about how the study should work and allow them to document ongoing treatments and doctor consultations.

The researchers primarily wanted to compare the difference in the proportion of patients who had a severe episode of pharyngitis within the five-month period.

What were the basic results?

Of 260 eligible participants, 86 took part. Most who were excluded either had too few previous episodes of tonsillitis, had chronic tonsillitis, or lived outside the study region. A further 42 declined to participate altogether. All patients in both groups were followed-up at five months.

The main analysis found that at follow-up, one patient in the control group and no patients in the tonsillectomy group had experienced an episode of severe pharyngitis. This difference was not statistically significant.

When looking at other outcomes, the researchers found 17 (45%) patients in the control group and two (4%) in the tonsillectomy group had consulted a doctor for pharyngitis (difference 38%, 95% confidence interval 22% to 55%). This difference was statistically significant.

Significant differences that favoured the tonsillectomy group were also found for:

the number of patients experiencing acute pharyngitis over the five-month period
the overall rate of pharyngitis
the number of days with throat pain, fever, runny nose and cough
days absent from school or work

How did the researchers interpret the results?

The researchers concluded that, "Adult patients with recurrent pharyngitis of any origin had very few severe episodes of pharyngitis, regardless of whether they underwent tonsillectomy."

However, "Patients who did undergo surgery had fewer episodes of pharyngitis overall and less frequent throat pain than did patients in the control group. These reductions resulted in fewer medical visits and fewer absences from school or work."

Conclusion

This small-scale research adds relatively little evidence to settle the debate about when and how often to use tonsillectomy, as the media outlined.

The research has many limitations to consider that make it less reliable, or applicable to the UK:

This was a very small study based in Finland that looked at outcomes for just 86 patients. This means it may not be representative of people who would generally be considered for tonsillectomy in the UK.
The waiting time for surgery in Finland is restricted to six months by law, so the research could only follow-up people in the control group for around five months before they had surgery. This limits the study's ability to assess whether a significant number of the control group would spontaneously improve during a longer follow-up period, and leaves open the possibility that the beneficial effect of tonsillectomy may be temporary if pharyngitis recurred after six months.
There is likely to have been bias in the selection of the control group, as they were told that they would undergo surgery eventually. Those that wanted surgery earlier are likely to have declined to participate in the study.
There were relatively few eligible cases of recurrent pharyngitis in this study, shown by the fact only 86 were recruited over a three-year period. For this reason, it does not seem to be a particularly common problem for people. However, it does suggest that tonsillectomy may be beneficial to this group of patients.
The study authors highlight a recent Cochrane systematic review on tonsillectomy for recurrent tonsillitis that found only a single trial involving adults. It included adults severely affected by a specific infective cause (recurrent group A streptococcal pharyngitis, known as 'strep throat'). This means there is relatively little evidence available on this topic to reliably inform decision-making.
Tonsillectomy is usually carried out under a general anaesthetic and, as with all surgeries, carries a risk of complications. A common complication is bleeding at the site where the tonsils are removed. This is estimated to affect around one in 30 adults and one in 100 children. Minor bleeding is not usually cause for concern and heals itself, but heavier bleeding can cause vomiting and coughing up blood, requiring immediate medical advice.

This research adds little to the debate about how many tonsillectomies the NHS should be performing. The debate rumbles on, largely because there is a lack of good quality evidence that can tell us how effective tonsillectomies are for adults.