Discussion
We performed a pilot, monocenter, retrospective cohort study to
evaluate the efficacy and perceived satisfaction of 3-year SLIT inreal-life , measured by a validated questionnaire, in a population
of mono- or poly-sensitized patients with allergic rhinitis and/or
asthma. As expected, the SLIT significantly contributed in modifying the
disease course in patients suffering from allergic rhinitis and asthma
as well asthma with rhinitis. The positive impact of treatment has been
assessed by significant changes in perceived efficacy in patients,
rescue medication use; perceived satisfaction in patients; disease
control and impact on quality of life; and number of disease
exacerbations. Significant changes have also been recorded in the
frequency of symptoms of patients suffering from asthma and asthma with
allergic rhinitis; however, no changes were reported in the allergic
rhinitis group. The absence of significant changes has been related to
the small sample size: only six patients were suffering from allergic
rhinitis.
Confirming the efficacy of SLIT, the perceived satisfaction for all
enrolled patients was high, and it is reasonable to hypothesize that
these data were related to the improvement in clinical outcome. Sparse
studies investigated the efficacy/perceived satisfaction ratio, which is
crucial in obtaining a high treatment adherence [13-15]. Moreover,
when this issue was investigated, several biases were affecting the
results, such as conflict of interests [13, 14]. In our study, all
patients reported a high rate of satisfaction, more probably as a
consequence of efficacy treatment. It has been reported that the reasons
for premature cessation of AIT are the inability to reach the clinical
centre, the ineffectiveness of therapy, and the long course of treatment
[16]. Herein, the nature study allowed us to enrol patients that
were highly motivated to start treatment as well as to participate in a
study in the absence of a strict protocol. All these factors resulted in
high treatment adherence as 60/70 (85.7%) of all enrolled patients
declared themselves very satisfied, 6/70 (8.57%) much satisfied, and
4/60 (5.71%) satisfied. Adherence is the key to ensure SLIT
effectiveness, as poor adherence is a potential factor affecting
negatively the efficacy of AIT. In line with this finding, all enrolled
patients completed at least three years of treatment, showing 100%
spontaneous adherence to the prescribed treatment. Contrary to other
studies in which a high treatment adherence was obtained thanks to the
help of nurse interventions, frequent scheduled visits and telephone
calls [17-19], herein, our patients showed 100% spontaneousadherence to the prescribed treatment. In this regard, we believe that
patients were obtaining real benefit from the treatment probably since
the first year of the therapy; thus, a good efficacy achieved during the
first year of treatment could be considered as a favourable prognostic
factor for treatment adherence for the next two years with long-lasting
positive effects in real-practice. Also, only a continuous AIT for a
period of at least 3 years modifies the course of the disease and
ensures the long-term remission of symptoms for several years
[20-23]. RCTs and observational studies on treatment adherence
reported that the discontinuation rate for SCIT is approximately 22%,
34%, and 26% from one to three treatment years, respectively; and, for
SLIT is 42%, 29%, and 27% from one to three treatment years [24,
25]. Herein, we firstly reported that the treatment adherence for SLIT
was 100% troughtout the study duration. Similar to other chronic
conditions, allergic diseases require ongoing care to minimize their
impact, improve health outcomes, prevent clinical worsening and
comorbidities, and reduce healthcare costs [26]. Nevertheless, it
has been estimated that only the half of patients with chronic
conditions take their medications as prescribed; since several factors
affect the patients’ability to follow treatment recommendations
correctly [26, 27]. We strongly believe that the complete treatment
adherence in our population can primarily be attributed to the study
design. In RCTs, patients are strictly selected and monitored over time
to limit bias; and, when patients differ from that set out, they are
excluded from the final study results. Conversely, more reliable data
can be derived from real-life studies, since a combination of
strategies, such as educational plans and regular assessments, can be
more easy applicable [28].
Moreover, the novelty and strength of our study were also to show the
efficacy and perceived satisfaction of 3-year SLIT via areal-life design. Although the health sciences community selects
RCTs as the main tool able to investigate and evaluate clinical
interventions with the lowest risk of bias, the obtained data does not
ever fit with the general population; thus, the translation and the use
of data obtained from RCTs in real-practice can be questionable. Looking
specifically at RCTs performed in AIT, several issues could explain the
inadequacy of RCTs in AIT. The studies generally have short duration and
are limited to one pollen season, and it is well known that the
potential of AIT in preventing new sensitization and onset of allergic
diseases is strictly correlated with the duration treatment, and at
least 3-year treatment course is recommended [29, 30].
The RCTs are designed to test if the selected treatment is working, but
they do not evaluate if the treatment works in real-life. Aiming
to limit any factor that could potentially influence final
results, RCTs are designed in compliance with a rigid and strictprotocol; however, the latter is not the same adopted by all RCTs; thus,
a “within-study” and “between-study” heterogeneity is extensively
reported among different trials [6]. Moreover, the RCTs are
investigating an experimental treatment in a selected group of patients
who must respect the study’s inclusion criteria [6]. Any protocol
modification is foreseen for patients who do not strictly meet the
inclusion criteria or unforeseen events [6]. Thus, it can
happen that, due to several reasons (e.g., age, disease severity,
comorbidities, use of concomitant medications, etc), a cluster of
patients, from which it could be possible to extract potential and
interesting data, must be excluded from the study with a gap in
knowledge of the investigated treatment in real-practice.
Whether on one hand the “one-size-fits-all” approach can provide the
opportunity to apply a treatment for a large population; on the other
hand, it does not work for everyone. A treatment defined as
“effective” in an ideal clinical setting can not give specific
quantifiable answers under individual cases in a routine clinical
setting. Tailor healthcare approach and treatment to meet the specific
needs of each patient. is urgently needed as only a “sartorial”
approach can provide an individual’s unique molecular, lifestyle, and
clinical information.
We strongly believe that real-world studies, using data collected
in everyday clinical settings, can hold the promise of providingreal data to maximize the applicability and generalizability of
an intervention. Nevertheless, we do not aim to fule a war between a
“wrong” and “right” research approach rather we want to shift form adichotomous to an integrated perspective, able to combine
the strengths of each research method -the prospective, randomized, and
analytical design of the RCTs with more representative and generalizable
data of real-life studies- and exceed the limits of restrictive
inclusion and exclusion criteria of RCTs and the risk of low-quality
control of the surrounding data collection and susceptibility to
multiple sources of bias occurring in real-life studies.