Al Jaghsi et al. BMC Oral Health (2021) 21:446
https://doi.org/10.1186/s12903-021-01811-w
RESEARCH Open Access
VALIDITY AND RELIABILITY OF NEW
Validity and reliability
INSTRUMENTS of new instruments
FOR MEASURING PATIENT
for measuringWITH
SATISFACTION patient satisfaction DENTURES
REMOVABLE
with removable dentures, Arabic Version
Ahmad Al Jaghsi1,2,3*, Musab Saeed1, Salem Abu Fanas1, Ahmed Yaseen Alqutaibi4 and Torsten Mundt3
Abstract
Background: The psychometric properties of self-administered instruments for measuring patient satisfaction with
removable dentures should be tested before inviting patients to express their opinions. This study aimed to evaluate
the validity and reliability of new instruments in the Arabic language that measure patient satisfaction with all types
of removable dentures.
Methods: A three-step methodology was used to translate and test the instruments. In step one, the instruments
were translated from tested German instruments to develop the pilot questionnaires. In step two, the face validity
of the pilot questionnaires was tested through three rounds of interviews. There were 15, 13, and 15 participants
per round, respectively. At the end of every round, the results of the interviews were discussed with an expert panel.
The expert panel confirmed the form and the type of questionnaires’ adjustments before a new round of interviews
began. At the end of step two, the final form of the questionnaires was reached. In step three, 235 questionnaires
were distributed to 133 participants to estimate the construct validity of the upper jaw and the lower jaw question-
naires. After one week, the participants were asked to complete the questionnaires again. A total of 102 question-
naires were returned and used to assess the instruments’ reliability. Factor analysis was used to assess the construct
validity. The intraclass correlation coefficient and Cronbach’s alpha were used to estimate the reliability and suitability
of the items in the indexes.
Results: The result of step one was two pilot questionnaires. The pilot questionnaires were adjusted in step two.
At the end of step two, the questionnaires proved to have good face validity. Factor analyses in step three revealed
that only one factor could be retained. The one-factor model explained 60.95% and 63.06 of the total variance of the
upper jaw and lower jaw questionnaires, respectively. The items in every questionnaire shared the same cluster and
could be summed to form an upper jaw index and lower jaw index that reflected patient satisfaction with removable
dentures. Cronbach’s alpha values indicated excellent internal consistency and reliability for the upper jaw question-
naire (α = 0.91) and the lower jaw questionnaire (α = 0.92). Intraclass correlation coefficient values ranged from 0.72 to
0.95, which can be considered “moderate” to “excellent”.
Conclusions: The Arabic version of questionnaires and indexes assessing patient satisfaction with upper and lower
removable dentures are reliable and valid self-administered instruments.
*Correspondence: ;
1
College of Dentistry, Restorative Department, Clinical Sciences
Department, Ajman University, University Street, Al jerf 1, Ajman, United
Arab Emirates
Full list of author information is available at the end of the article
© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the
original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or
other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line
to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory
regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this
licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco
mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
, Al Jaghsi et al. BMC Oral Health (2021) 21:446 Page 2 of 10
Keywords: Questionnaire, Index, Patient satisfaction, Removable denture, Validity, Reliability
Introduction Construct validity reflects how far the questionnaire
Patient satisfaction has gained increasing attention or the index truly evaluates the hypothesis, theory or
from dental health providers and the medical indus- themes under examination. It should reveal that the
try. Consequently, different methods and strategies ‘items’ (questions) scores on a specific domain anticipate
have been developed and implemented to measure the theoretical trait it claims to predict [12]. One of the
and improve patient/customer satisfaction. Neverthe- good and most widely used methods to estimate con-
less, evidence shows that more work in this field is still struct validity is confirmatory factor analysis [13].
needed [1]. Patient satisfaction can be estimated effec- Instrument reliability means that the instrument con-
tively through two important methods: interviews and sistently reflects the construct that it is measuring by giv-
questionnaires [2]. ing the same score if used over time or across multiple
By asking patients the right questions, there is almost administrations. The stability of scores over time requires
limitless and useful information that can be collected. that all other things be equal [14]. This means that in our
In some cases, relying on observation or clinical exami- study, no adjustment or changes occurred intraorally or
nation to collect the needed information is not a prac- to the removable dentures (RDs) between the first and
tical approach. Instead, it is preferable to ask a valid second assessments. Intraclass correlation coefficients
and reliable set of questions. A questionnaire is a type (ICCs) are an important element for test–retest reliability
of communication medium between the participants assessment [15].
and the researcher [3]. The role of a questionnaire is to Internal consistency, as described by Revelle, is the
provide a standardized approach across all participants degree to which all items quantify the same construct
[3]. In self-administered questionnaires, questions [16]. One of the widely used methods for estimating the
are asked in the same way and in a format that both internal consistency of a questionnaire or index is Cron-
matches the needs of the study and is convenient for bach’s alpha. It helps quantify the reliability of a score and
participants. If these conditions are not met, it will be summarize the data from multiple questionnaire items
challenging for the researcher to interpret the answers. [17].
First and foremost, survey instruments should have Although patient satisfaction is an important subject,
special psychometric properties when they are self- we could not find in the dental literature a valid and reli-
administered. Annie G. defined the psychometric able instrument in the Arabic language that measures
properties of an instrument as “the construction and patient satisfaction with RDs.
validation of the measurement instrument” [4]. These The aim of this study was to evaluate the validity and
properties reflect the instrument’s reliability and valid- reliability of new instruments in the Arabic language
ity [5]. Patient satisfaction is a subjective assessment that measure patient satisfaction with all types of RDs.
[6]. Therefore, the psychometric properties of the The Arabic version was translated from valid and reliable
instrument should be tested before inviting patients German instruments [7].
to express their opinions. If the study fails to satisfy
this necessity, the collected data will be questionable, Method and materials
and the survey conclusion cannot be trusted [7]. That The study is in full accordance with the World Medical
is, testing the validity and reliability of the question- Association Declaration of Helsinki. The medical ethics
naire helps the researcher estimate the level of accuracy committee at Ajman University approved the study. All
and consistency of the collected data. Under these two participants gave their written informed consent to all
components, there are several subtypes: face validity study procedures.
and construct validity, on the one hand, and reliability The participants included in the study were Arabic-
and internal consistency, on the other hand. speaking patients who had a partial or complete RD. RDs
Face validity may best be understood as reflecting can be tissue-, teeth-, implant- or combined-supported
the extent to which the instrument measures what it is dentures. The participant should be adapted and wearing
intended to measure [8]. Face validity, which is a form their RDs for at least two months. If patients had intra-
of content validity, plays an essential role in construct- or extraoral pathological findings, were not wearing their
ing and testing the questionnaire [9]. This type of valid- RDs regularly or were classified in one of the ten main
ity can be tested through expert assessment of items groups of the international classification of diseases or
and interviews [10, 11]. mental and behavioral disorders [18], they were excluded
https://doi.org/10.1186/s12903-021-01811-w
RESEARCH Open Access
VALIDITY AND RELIABILITY OF NEW
Validity and reliability
INSTRUMENTS of new instruments
FOR MEASURING PATIENT
for measuringWITH
SATISFACTION patient satisfaction DENTURES
REMOVABLE
with removable dentures, Arabic Version
Ahmad Al Jaghsi1,2,3*, Musab Saeed1, Salem Abu Fanas1, Ahmed Yaseen Alqutaibi4 and Torsten Mundt3
Abstract
Background: The psychometric properties of self-administered instruments for measuring patient satisfaction with
removable dentures should be tested before inviting patients to express their opinions. This study aimed to evaluate
the validity and reliability of new instruments in the Arabic language that measure patient satisfaction with all types
of removable dentures.
Methods: A three-step methodology was used to translate and test the instruments. In step one, the instruments
were translated from tested German instruments to develop the pilot questionnaires. In step two, the face validity
of the pilot questionnaires was tested through three rounds of interviews. There were 15, 13, and 15 participants
per round, respectively. At the end of every round, the results of the interviews were discussed with an expert panel.
The expert panel confirmed the form and the type of questionnaires’ adjustments before a new round of interviews
began. At the end of step two, the final form of the questionnaires was reached. In step three, 235 questionnaires
were distributed to 133 participants to estimate the construct validity of the upper jaw and the lower jaw question-
naires. After one week, the participants were asked to complete the questionnaires again. A total of 102 question-
naires were returned and used to assess the instruments’ reliability. Factor analysis was used to assess the construct
validity. The intraclass correlation coefficient and Cronbach’s alpha were used to estimate the reliability and suitability
of the items in the indexes.
Results: The result of step one was two pilot questionnaires. The pilot questionnaires were adjusted in step two.
At the end of step two, the questionnaires proved to have good face validity. Factor analyses in step three revealed
that only one factor could be retained. The one-factor model explained 60.95% and 63.06 of the total variance of the
upper jaw and lower jaw questionnaires, respectively. The items in every questionnaire shared the same cluster and
could be summed to form an upper jaw index and lower jaw index that reflected patient satisfaction with removable
dentures. Cronbach’s alpha values indicated excellent internal consistency and reliability for the upper jaw question-
naire (α = 0.91) and the lower jaw questionnaire (α = 0.92). Intraclass correlation coefficient values ranged from 0.72 to
0.95, which can be considered “moderate” to “excellent”.
Conclusions: The Arabic version of questionnaires and indexes assessing patient satisfaction with upper and lower
removable dentures are reliable and valid self-administered instruments.
*Correspondence: ;
1
College of Dentistry, Restorative Department, Clinical Sciences
Department, Ajman University, University Street, Al jerf 1, Ajman, United
Arab Emirates
Full list of author information is available at the end of the article
© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the
original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or
other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line
to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory
regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this
licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco
mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
, Al Jaghsi et al. BMC Oral Health (2021) 21:446 Page 2 of 10
Keywords: Questionnaire, Index, Patient satisfaction, Removable denture, Validity, Reliability
Introduction Construct validity reflects how far the questionnaire
Patient satisfaction has gained increasing attention or the index truly evaluates the hypothesis, theory or
from dental health providers and the medical indus- themes under examination. It should reveal that the
try. Consequently, different methods and strategies ‘items’ (questions) scores on a specific domain anticipate
have been developed and implemented to measure the theoretical trait it claims to predict [12]. One of the
and improve patient/customer satisfaction. Neverthe- good and most widely used methods to estimate con-
less, evidence shows that more work in this field is still struct validity is confirmatory factor analysis [13].
needed [1]. Patient satisfaction can be estimated effec- Instrument reliability means that the instrument con-
tively through two important methods: interviews and sistently reflects the construct that it is measuring by giv-
questionnaires [2]. ing the same score if used over time or across multiple
By asking patients the right questions, there is almost administrations. The stability of scores over time requires
limitless and useful information that can be collected. that all other things be equal [14]. This means that in our
In some cases, relying on observation or clinical exami- study, no adjustment or changes occurred intraorally or
nation to collect the needed information is not a prac- to the removable dentures (RDs) between the first and
tical approach. Instead, it is preferable to ask a valid second assessments. Intraclass correlation coefficients
and reliable set of questions. A questionnaire is a type (ICCs) are an important element for test–retest reliability
of communication medium between the participants assessment [15].
and the researcher [3]. The role of a questionnaire is to Internal consistency, as described by Revelle, is the
provide a standardized approach across all participants degree to which all items quantify the same construct
[3]. In self-administered questionnaires, questions [16]. One of the widely used methods for estimating the
are asked in the same way and in a format that both internal consistency of a questionnaire or index is Cron-
matches the needs of the study and is convenient for bach’s alpha. It helps quantify the reliability of a score and
participants. If these conditions are not met, it will be summarize the data from multiple questionnaire items
challenging for the researcher to interpret the answers. [17].
First and foremost, survey instruments should have Although patient satisfaction is an important subject,
special psychometric properties when they are self- we could not find in the dental literature a valid and reli-
administered. Annie G. defined the psychometric able instrument in the Arabic language that measures
properties of an instrument as “the construction and patient satisfaction with RDs.
validation of the measurement instrument” [4]. These The aim of this study was to evaluate the validity and
properties reflect the instrument’s reliability and valid- reliability of new instruments in the Arabic language
ity [5]. Patient satisfaction is a subjective assessment that measure patient satisfaction with all types of RDs.
[6]. Therefore, the psychometric properties of the The Arabic version was translated from valid and reliable
instrument should be tested before inviting patients German instruments [7].
to express their opinions. If the study fails to satisfy
this necessity, the collected data will be questionable, Method and materials
and the survey conclusion cannot be trusted [7]. That The study is in full accordance with the World Medical
is, testing the validity and reliability of the question- Association Declaration of Helsinki. The medical ethics
naire helps the researcher estimate the level of accuracy committee at Ajman University approved the study. All
and consistency of the collected data. Under these two participants gave their written informed consent to all
components, there are several subtypes: face validity study procedures.
and construct validity, on the one hand, and reliability The participants included in the study were Arabic-
and internal consistency, on the other hand. speaking patients who had a partial or complete RD. RDs
Face validity may best be understood as reflecting can be tissue-, teeth-, implant- or combined-supported
the extent to which the instrument measures what it is dentures. The participant should be adapted and wearing
intended to measure [8]. Face validity, which is a form their RDs for at least two months. If patients had intra-
of content validity, plays an essential role in construct- or extraoral pathological findings, were not wearing their
ing and testing the questionnaire [9]. This type of valid- RDs regularly or were classified in one of the ten main
ity can be tested through expert assessment of items groups of the international classification of diseases or
and interviews [10, 11]. mental and behavioral disorders [18], they were excluded
