DISCUSSION
Our study is the first multicentre study which has evaluated adherence
to SCIT with aeroallergens during the COVID-19 pandemic and its
influence on the short-term clinical outcomes in real-life. We observed
that in half of the patients (53.8%), SCIT injections were delayed and
one third (31.8%) of the patients were non-adherent during COVID-19
pandemic. Delays in SCIT administration have led to deterioration in the
AIT effectiveness and QoL, and the deterioration was even greater in the
non-adherent patients.
Adherence to long-term treatments in chronic diseases is very crucial
for the success of the treatment3. The definition of
adherence to SCIT differs in studies, however we referred to a previous
study which was conducted by our group and considered the cut-off time
interval for being non-adherent as 2 months
accordingly2. Moreover, we also determined the
clinical results of shorter delays of less than 2 months in injection
intervals in a separate patient group in order to strengthen our
findings. By this way, we have captured all significant clinical
consequences of delays in injection intervals. Since our study is the
first adherence study during the pandemic, we could only compare our
results with previous SCIT adherence studies published before the
pandemic. In the majority of the adherence studies on SCIT, the
adherence rates are less than 70%2,10-13.
Furthermore, they are even lower according to real-life
data2,14,15. In our study, 68.2% of the patients were
adherent to SCIT during the pandemic. We can speculate that this
acceptable adherence rate in our study may be due to continuous
treatment with appropriate preventive measures applied despite the
negative effects of the pandemic and the close cooperation that had been
established between the allergists and the patients in the study centres
before the pandemic.
As a main finding of our study, delay in SCIT administrations led to
deterioration in AR symptoms and QoL of our patients. Delays of less
than 2 months between subsequent SCIT injections worsened QoL and
symptom scores in Group 2 patients whereas in the non-adherent group MSs
were additionally disrupted. Therefore, we suggest that it is important
to continue SCIT injections without giving intervals more than
recommended in order not to affect the short-term effectiveness of AIT
even during a pandemic16. Prolonged intervals in the
SCIT applications is also an important issue to make appropriate dose
adjustments to restart SCIT after gaps in the
administration17. In our study, after interruptions of
maintenance doses especially in non-adherent patients, dose adjustments
starting with frequent lower dose injections caused frequent hospital
visits which can probably bring additional burden on the healthcare
system.
The two main reasons of non-adherence to SCIT in our study were using
public transport for reaching the hospital and receiving SCIT with HDMs.
In accordance with our findings, a study from the USA reported that one
of the reasons of premature cessation of SCIT was the inconvenience of
travel18. It is very obvious that patients using
public transportation during a pandemic may discontinue SCIT injection
visits in order to reduce the risk of being infected. In a study,
adherence to pollen SCIT was higher than the SCITs with other
allergens14 while in other studies no relationship
between allergen type and adherence was observed2,18.
Since our study was conducted in the pollen
season19,20, the adherence in patients receiving
pollen SCIT was better than those receiving SCIT with HDMs. We assume
that these patients were worried about having severe AR and/or asthmatic
symptoms during the pollen season corresponding to the pandemic
therefore received more regular SCIT injections. However, we did not
observe any significant changes in the scores of the patients who
received pollen or HDM SCIT before and during the pandemic. Moreover,
VAS-symptom, VAS-QoL, TSS-6 and MS did not deteriorate during pollen
season for most of the pollen SCIT patients who received the treatment
regularly.
Among demographic factors; age, gender, occupation and socioeconomic
status were related to non-adherence to SCIT in recent
studies2,14,18,21,22. However, we did not observe any
association between these factors and adherence. This difference might
be due to the fact that the COVID-19 pandemic has similarly affected
people with different demographic characteristics. Furthermore, having
diagnosis of AR or AR with asthma was not related to adherence to SCIT
administrations similar to some adherence
studies2,12,23.
Our study focused on the effects of patient behaviours on SCIT
application during the pandemic since the physician behaviours were not
significantly different from the pre-pandemic period. However, the delay
in SCIT applications may also occur due to the clinical practice
preferences of the physicians. In a current international EAACI survey
study investigating the AIT practice behaviours of physicians during the
pandemic, it has been shown that 41% of the participants extended the
application period and 13% paused it during the
pandemic24. We believe our study is important in
showing the short-term clinical consequences in case of delays between
SCIT injections depending on patient behaviours and it also supports the
recent AIT recommendations of EAACI1.
As a limitation of our study, we have compared our findings with results
of previous adherence studies conducted during normal life while
interpreting the clinical results of treatment disruptions related to
the pandemic. However, social restrictions affecting different aspects
of daily life and mental changes caused by the pandemic may generate its
own dynamics which may limit the comparison of study results with
previous studies. In addition, whereas adherence studies usually
comprise of long periods of AIT, our study has presented adherence to
SCIT for a short-term period of 6 months. However, we plan to further
evaluate the same patient groups for longer periods to show long-term
effectiveness of SCIT and adherence rates in relation to the pandemic.
Finally, our results are convincing, regarding the high number of
patients, similar median duration of maintenance phases of SCIT before
the study between the groups and similar initial symptom, medication and
quality of life scores, although the patient groups were not homogenous
in terms of allergens applied during the SCIT injections, sensitivity
and the presence of asthma.
In conclusion, in the current study, the negative effects of COVID-19
pandemic on adherence to SCIT administrations and short-term clinical
efficacy have been demonstrated in real-life. We believe that it is
important to continue SCIT administrations by providing the necessary
precautions in allergy clinics during a pandemic in order to maintain
the clinical efficacy of the treatment.