Lifestyle variables (table
4)
The comparison of the two phenotypes showed no evidence of a difference
in smoking (p=0.25) or home location (p=0.12), but did show a difference
in alcohol consumption, with CRSwNP participants likely to drink more
alcohol than those with CRSsNP (p=0.032).
Discussion
Key results:
No demonstrable differences were found for the key socioeconomic
variables between the two groups, nor were there any differences in
lifestyle variables other than alcohol consumption being higher in those
with CRSwNP. Aside from confirmation of asthma being more common in
CRSwNP, it was notable that this group complained less of URTIs. CRSsNP
participants showed evidence of lower HRQoL scores in respect of body
pain. The difference in alcohol consumption may be explained by the
gender differences. In the UK men consume more alcohol than women. The
2018 Health Survey for England showed the mean male weekly alcohol
consumption in units was 15.5 while for females it was
923. The same survey also found that 14% of male
responders were teetotal compared to 21% of female responders. Our data
shows that males are significantly more likely to suffer from CRwNP than
females.
Interpretation:
CRES is the largest epidemiological study of CRS and the first study
since the 2001 Sinonasal Audit (24) to collect detailed information on
socioeconomic variables in the UK. As mentioned above, a systematic
review in 2018 concluded that smoking, social deprivation and low
socioeconomic level appear to have a direct correlation with
rhinosinusitis10. They also concluded that education
level, and exercise and diet appear to have a more complex relationship
with CRS. In the Korean KNHANES study CRSwNP was more prevalent in rural
areas and with a lower level of education, obesity, increased amounts of
smoking and alcohol consumption, and comorbid asthma8. It is possible that some of these difference are
accounted for by ethnic differences in the underlying pathophysiology25.
A small study (n=186) comparing patients with AFRS and CRS found that he
CRS cases were predominantly white and older at the time of diagnosis
with higher income levels. They found no associations between disease
severity, socioeconomic status, and demographic factors within the CRS
groups 26. In a North American study published in
2019, Beswick et al reported that their analysis of 392 patients showed
that medical insurance status and male gender were significantly
associated with worse smell test scores, and also that higher household
income and lower age led to better outcomes on health related quality of
life scores (SNOT-22) following sinus surgery (27). In this study 36%
of the cases were CRS with nasal polyps (CRSwNP) and 37% reported
asthma. Differing findings and differing diagnostic and sampling methods
across various studies and healthcare systems suggest that the true
picture has yet to be clarified.
Whilst our CRES study has not demonstrated any evidence that
socioeconomic deprivation is a risk factor for CRS or either of the two
main phenotypes, other related work on the cost of managing CRS has
shown higher out-of-pocket expenditure, primary care and secondary care
utilisation, and time lost from work compared to those without CRS28. This study estimated an annual average out of
pocket expenses of £304.84 secondary to CRS over 3 months, with a
5.3-fold greater spending on over-the-counter medication when compared
to the general population and an association with an average 18.7 missed
workdays per year. For those in lower socioeconomic groups, they are
more likely to be disadvantaged by this implication. This effect appears
to have been more pronounced in a private healthcare system (27) but may
be less apparent in the National Health Service where direct healthcare
is free at the point of service, excluding prescription costs (England
not Scotland).
It is an interesting observation that those with CRSwNP reported higher
rates of alcohol consumption than those with CRSsNP given our previous
analysis regarding symptom exacerbation with wine, which showed
significantly higher rates in the CRSwNP phenotype (29). This
association between dietary salicylates and symptom exacerbation
requires further investigation to better understand the link and the
presence of any dose-dependent response.
Limitations
The CRES study design has certain limitations, whilst the diagnosis was
made by a clinician, the remaining data was self-reported and may
therefore predispose to recall bias. Secondly although we collected
information on household occupancy, we didn’t collect information on
number of bedrooms and the potential for overcrowding. In asthma,
overcrowding has been shown to have a positive 30 and
a negative 31 correlation with respiratory symptoms
with no clear relationship in other studies 32, so
there is not a clear relationship in the lower respiratory tract. Our
study has also sampled a mainly British White ethnic demographic and may
not fully reflect the wider population in the UK today.
Generalisability
CRES is a cross sectional UK based study incorporating a variety of the
CRS population from across the country presenting to secondary care. The
CRES study does not necessarily capture the whole CRS spectrum as mild
sufferers may be managed by primary care alone and may therefore be
underrepresented. In contrast to other studies, CRS was diagnosed by ENT
specialists according to accepted diagnostic guidelines (EPOS 2012)
(16); other existing studies have relied on self-diagnosis and/or used
different criteria making direct comparisons with the existing
literature more complicated. Whilst we realise EPOS2020 (1) has now
superseded EPOS2012, the former was relevant at the time of the study
being conducted. In the current era making comparisons between endotypes
such as those with or without Type 2 mediated inflammation may provide
further clinical relevance, but for now these are perhaps not adequately
defined.