Pilot study – data extraction
form
1
Introduction
The studies found in the rapid scoping exercise presented the outcome, or change in
treatment plan, in different ways. A common measure is an increase or decrease in length
or width of a planned dental implant. Nevertheless, a difficulty arises from the type of
implant system used. Some studies measured the change in implant length or width. The
difficulty arises because implants change dimensions in steps and this is dependent on the
type of implant system used. For example, in one study, Brӓnemark system implants are
available in widths of 3.3mm, 3.75mm, 4mm and 5mm. In another, Straumann implants are
available in widths of 4.1mm and 4.8mm. Other studies record change in treatment decisions
about bone grafting or sinus augmentation surgery. It was, therefore, necessary to design a
data extraction form that captured all variations and commonality of outcome between the
studies so that analysis could be planned. In addition, other characteristics of the studies
had to be recorded to enable synthesis. The intention was that further referral to original
publications would be kept to a minimum once data extraction had been carried out.
2
Materials and methods
The starting point was the data extraction form used by Albon et al in their similar
neuroimaging review. This is reproduced in Appendix A. Preliminary wording changes were
made appropriate to the current review. The form was labelled “Data Extraction Form v1”
and was piloted on the five rapid scope studies as follows:
Diniz 2008 4, Frei 2004 5, Reddy 1994 6, Schropp 2001 7 and Schropp 2011 8
The separate section on subgroup analyses was not thought to be necessary since it largely
reproduced data which was captured in other parts of the form.
Data Extraction Form v1 is reproduced in Appendix B
3
Results
Several problems were identified with Data Extraction Form v1:
Only one of the studies in the rapid scoping exercise used true three dimensional imaging.
In this case, medical computed tomography. Other studies used conventional spiral
tomography. Whilst this produces a cross sectional image, it may be considered not to be
true three dimensional imaging. Therefore the wording was changed from “3D imaging” to
“X sectional or 3D imaging”
The question on age was very specific, asking for the mean, range and standard deviation.
Not all of this information was available in all the studies. The question was therefore
amended to request whatever information was provided by authors.
The inclusion and exclusion criteria reported in the studies were often extensive, requiring
more space than available on the form. This answer box was therefore expanded.
The number of patients in the study was asked twice. One of these questions was removed
to prevent duplication.
The lengths and widths of implants available for selection was important for the reasons
discussed in the introduction. This was not recorded in the form and so was added.
The question on bone augmentation could cover both the addition of bone and, for example,
sinus augmentation surgery. One of the studies made a distinction between bone grafting
and other surgical procedures. This was, therefore, amended to ask two separate
questions. The first concerned bone grafting and the second “other surgical procedures”
which would include sinus augmentation.
Where a question was not addressed in a study it was convenient to write “NS” rather than
“Not stated”. In the revised version, therefore, the reviewer was prompted to do this.
In the rapid scoping studies, the reason given for undertaking imaging was always to assess
available bone prior to implant placement in the partly or fully edentulous patient. Therefore,
it was expedient to answer the question about the reason for scanning only if this was
different. The revised form advises accordingly. The question about the “Presenting
problem” was also removed as it was a duplication of the same information.
The question about clinical information was changed so that it was only answered if no
clinical examination had been carried out.
It was also considered that the section on outcomes should be expanded to capture all
variations of outcome measure. It was also amended to record more global, dichotomous
outcome measures such as whether implant size changed or not. This was an attempt to
capture data that may be common to the largest number of studies.
Finally, a version of the form was produced in Microsoft Excel so that data could be more
expediently copied, manipulated and analysed. The printed version of the form is presented
in Appendix C.
4
Conclusion and discussion
The data extraction form does now seem to capture the required data. This should now be
trialled with a small number of co-reviewers to assess its clarity, ease of use and
effectiveness.
5
Post script
Following discussion, a further refinement was made to the data extraction form to include a
question about wash out periods. In other words, the time between the “Before” and “After “
parts of the study. The full form in its Microsoft Excel form is shown in Appendix D.
Appendix A – Data extraction form of Albon et al.
Appendix B
Data Extraction Form v1
(Adapted from Albon et al.)
Name of assessor
Study details
Author; year, trial name
Country(ies) and years of recruitment
Study design
Area of the mouth studied
Reason for scanning given
Conventional imaging technique used
3D imaging technique used
Setting (practice, hospital etc)
Comments:
Patient characteristics
Population
Number of patients
Age (years) Mean (SD) [range]
Sex Proportion male (%)
Presenting problem
Inclusion/exclusion criteria
Comments:
Evaluator characteristics
Number of evaluators
Types of evaluator (surgeon, radiologist etc)
Comments:
Interventions
Number of patients
Number of exclusions
Implant manufacturer(s)
Number of implants placed
How many anterior mandible?
How many posterior mandible?
How many anterior maxilla?
How many posterior maxilla?
Did evaluators carry out a clinical examination?
Was other clinical information available to
evaluators (study casts, clinical findings etc)
Comments:
Outcomes for analysis
What were the outcome measures?
In how many sites was a longer implant chosen
after 3D imaging available?
In how many sites was a shorter implant chosen
after 3D imaging available?
In how many sites was a wider implant chosen
after 3D imaging available?
In how many sites was a narrower implant
chosen after 3D imaging available?
In how many sites was bone augmentation
prescribed after 3D imaging but not after
conventional imaging?
In how many sites was bone augmentation
prescribed after conventional imaging but not
after 3D imaging?
Comments:
Definitions:
Implant site
The position of a single implant
Bone augmentation Sinus augmentation surgery or bone grafting of any type
Appendix C
Data Extraction Form v2
(Adapted from Albon et al.)
Where the required information is not stated in the study report write NS
Name of assessor
Study details
Author; year, trial name
Country(ies) and years of recruitment
Study design
Area of the mouth studied
Conventional imaging technique used
X sectional or 3D imaging technique used
Setting (practice, hospital etc)
Comments:
Patient characteristics
Population
Number of patients in study
Age (provide all information from study eg range,
SD etc)
Gender – state percentage male (%)
State presenting problem if not partial or
complete edentulism
Inclusion/exclusion criteria
Comments:
Evaluator characteristics
Number of evaluators
Types of evaluator (surgeon, radiologist etc)
Comments:
Interventions
Number of excluded patients
Number of patients after exclusions
Implant manufacturer(s)
Lengths and widths of implants available for
selection
Number of implants placed
How many anterior mandible?
How many posterior mandible?
How many anterior maxilla?
How many posterior maxilla?
Did evaluators carry out a clinical examination?
If no clinical examination carried out, was other
clinical information available to evaluators (eg.
study casts, clinical findings etc)
Comments:
Outcomes for analysis
What were the outcome measures?
(complete the sections which apply below)
If outcome measure is simply selection of a different implant
In how many sites was a different implant
selected after X sectional or 3D imaging
evaluated?
If outcome specifies selection of a different length or width
In how many sites was a different length of
implant selected after X sectional or 3D imaging
evaluated?
In how many sites was a different width of
implant selected after X sectional or 3D imaging
evaluated?
If outcome specifies selection of a longer, shorter, wider or narrower implant
In how many sites was a longer implant chosen
after X sectional or 3D imaging evaluated?
In how many sites was a shorter implant chosen
after X sectional or 3D imaging evaluated?
In how many sites was a wider implant chosen
after X sectional or 3D imaging evaluated?
In how many sites was a narrower implant
chosen after X sectional or 3D imaging
evaluated?
If outcome specifies prescription of additional procedures such as bone grafting, sinus lifting etc.
In how many sites was bone grafting prescribed
after X sectional or 3D imaging but not after
conventional imaging?
In how many sites was bone augmentation
prescribed after conventional imaging but not
after X sectional or 3D imaging?
In how many sites were other surgical procedures
prescribed after conventional imaging but not
after X sectional or 3D imaging?
In how many sites were other surgical procedures
prescribed after conventional imaging but not
after X sectional or 3D imaging?
Comments:
Can outcome data for anterior mandible only be
analysed?
Appendix D – Final version of data extraction form as a Microsoft Excel file.