163 / 264
the criteria). Studies reporting original data on the diagnostic
value of CT for the detection of otosclerosis in adult patients
with a clinical suspicion of otosclerosis were included. System-
atic reviews, opinion papers, non-human studies, and case
reports with less than 10 cases were excluded. Studies that
predominantly included pediatric patients were excluded.
Articles written in languages other than English, Dutch, Ger-
man, French, or Portuguese were excluded, as well as articles
published before the year 2000. Subsequently, the full texts of
eligible articles were independently screened by two reviewers
per selected article (I.W., A.v.W., S.H.B., C.F.D, S.A.K., and
M.R.). Additionally, PubMed and Web of Science were
searched for related articles, and reference lists of the selected
articles and systematic reviews on the topic were hand-searched
for titles not identified by our initial search. Discordances
regarding inclusion were solved by consensus discussion.
Study Assessment
The remaining articles were independently assessed for their
relevance and risk of bias by two reviewers (I.W. and A.v.W.)
using predefined criteria (see Table 2 for assessment criteria). A
similar version of this system was previously used in other
diagnostic systematic reviews (8–10). The criteria were classi-
fied as ‘‘satisfactory’’ (
*
), or ‘‘unsatisfactory or unclear’’ (
*
).
Relevance was scored to ensure that studies reported applicable
outcomes for a well-defined patient group (diagnostic values of
CT for patients with otosclerosis). Studies were classified as
having low relevance if two or more criteria were rated unsat-
isfactory. Studies were classified as having moderate relevance
if two criteria were rated satisfactory. The remaining studies
were classified as having high relevance.
Risk of bias was assessed by using predetermined criteria
based on the Cochrane Collaboration’s tool for assessing risk of
bias (11). Assessment of risk of bias involved the evaluation of
six criteria. Studies were classified as having low risk of bias if
five or more criteria were rated satisfactory and moderate risk of
bias if at least three criteria were rated satisfactory. The
remaining studies were classified as having a high risk of bias.
Articles that were rated moderate or high for relevance and
carried a low or moderate risk of bias were selected for further
review. Initial discordances between reviewers (I.W. and
A.v.W.) were again resolved by consensus discussion.
Data Extraction
Two authors (I.W. and A.v.W.) independently extracted
descriptive data regarding the study population, the index test
(CT), and the reference test (middle ear inspection and/or
histopathology) from the included studies. The true positive,
false positive, true negative, and false negative test results were
extracted to calculate the prevalence, sensitivity, specificity,
and post-test probabilities. The positive post-test probability
represents the probability of the presence of otosclerosis in case
of a positive CT. The negative post-test probability represents
the probability of the presence of otosclerosis in case of a
negative or normal CT. Positive and negative post-test proba-
bilities were calculated using likelihood ratios (LRs) (12).
Positive and negative LRs were calculated and subsequently
used to calculate the post-test odds of otosclerosis. The odds
were then translated to probabilities (12). Corresponding 95%
confidence intervals (95% CIs) were calculated according to
standard normal distribution (1.96 standard error). The
method described by Monsour et al. (13) was used to calculate
95% CIs for post-test probabilities.
RESULTS
Search and Selection
The search yielded 1,575 unique articles. After screen-
ing these articles on title and abstract and subsequently
full text, 1,558 articles were excluded on the basis of the
predefined inclusion and exclusion criteria (see Fig. 1 for
the criteria). Of the 17 articles (2,3,6,14–27) that were
considered eligible after full-text screening, another two
were excluded on the basis of language (Japanese and
Spanish) (14,15). The article by Marx et al. (16), and
Lagleyre et al. (17) described the same study population,
as well as the articles written by de Oliveira Vicente et al.
in 2004 and 2006 (24,25). Reference checking did not
result in any additional articles. Thus, in total 15 articles
describing 13 studies were selected for study assessment
(2,3,6,16–27).
Study Assessment
As shown in Table 2, two studies, described in three
articles, were considered highly relevant (16–18). In the
other 11 studies, patients with surgically confirmed oto-
sclerosis were included in the study population instead of
patients at risk of otosclerosis (2,3,6,19–27). The risk of
TABLE 1.
Search strategy (date of last search:
September 10, 2014)
Database
Search Strategy
Hits
PubMed
((computertomography[tiab] OR tomogra-
phy[tiab] OR CAT[tiab] OR CT[tiab] OR
HRCT[tiab] OR CTscan[tiab] OR scan[tiab]
OR imaging[tiab] OR radiologic[tiab] OR
radiology[tiab]) AND (otoscler [tiab] OR
otospong [tiab] OR stapes[tiab] OR
stirrup[tiab] OR stapedial[tiab] OR
ossicular[tiab] OR footplate[tiab] OR
stapedot [tiab] OR stapedec [tiab] OR
(middle AND ear AND inspection[tiab])))
OR ((tomography[MeSH Terms] OR
scan[MeSH Terms]) AND (otoscler [MeSH
Terms] OR stapes[MeSH Terms]))
1111
Embase
((computertomography:ab,ti OR tomogra-
phy:ab,ti OR cat:ab,ti OR ct:ab,ti OR
hrct:ab,ti OR ctscan:ab,ti OR scan:ab,ti OR
imaging:ab,ti OR radiologic:ab,ti OR radi-
ology:ab,ti) AND (otoscler :ab,ti OR
otospong :ab,ti OR stapes:ab,ti OR
stirrup:ab,ti OR stapedial:ab,ti OR
ossicular:ab,ti OR footplate:ab,ti OR
stapedot :ab,ti OR stapedec :ab,ti OR
(middle:ab,ti AND ear:ab,ti AND inspectio-
n:ab,ti)) OR ((otosclerosis/exp OR stapes/
exp) AND tomography/exp)) AND
[embase]/lim
1098
The Cochrane
Library
(((computertomography OR tomography OR
CAT OR CT OR HRCT OR CTscan OR
scan OR imaging OR radiologic OR radi-
ology):ti,ab) AND ((otoscler OR otospong
OR stapes OR stirrup OR stapedial OR
ossicular OR footplate OR stapedot OR
stapedec OR ‘middle ear inspection’):ti,ab))
OR (((otoscler OR stapes):kw) AND ((tom-
ography OR scan):kw))
8
I. WEGNER ET AL.
Otology & Neurotology, Vol. 37, No. 1, 2016
142