Measurement instruments

Here, you will find instruments with literature details which were developed and/or translated by the work group of “Patient participation”, as well as overview works on the theme of measurement instruments in shared decision-making.


Overview work of measurement instruments for SDM

Messung der Partizipativen Entscheidungsfindung – Übersicht über die Messinstrumente. [Measurement of Shared Decision-Making – A review of instruments.]

Scholl I, Koelewijn-van Loon M, Sepucha K, Elwyn G, Légaré F, Härter M and Dirmaier J Zeitschrift für Evidenz, Fortbildung und Qualität im Gesundheitswesen Volume 105, Issue 4, 2011, Pages 313-324.


In the last few years, the approach of shared decision-making (SDM) has gained in importance in many countries. As the concern is with a relatively young research area, new measurement instruments to assess SDM (decision-making process, outcome and associated constructs) are being developed on an ongoing basis. The goal of this study was to develop a structured overview of new developments in the area of measuring SDM, to give an outline of known scales and to provide an outlook regarding new developments. An electronic literature search and a manual search were conducted. Additionally, international experts from the research area were surveyed. Eight known instruments were found, which were subjected to further psychometric analyses, as well as eleven new scales and nine unpublished articles regarding measurement instruments. The results show a development in the direction of increased “dyadic measurement” (assessment of perspectives of physician and patient) of the SDM process. The international relevance of SDM can be discerned through the increased development of non-English scales. The majority of the instruments show good reliability but differ in terms of the efforts to validate them. Further studies are necessary to test most of the scales in psychometric terms. Moreover, the development of a theoretical framework concept for SDM measurements is called for in order to standardise the measurement of the different relevant constructs.

Key words: shared decision making; measurement; psychometrics; reliability; validity; review (As supplied by publisher)


The 9-item Shared Decision Making Questionnaire – patient version (SDM-Q-9)

The SDM-Q-9 was developed for use in research and clinical practice. It can equally be implemented for purposes of evaluation and quality assurance in the health care system. The SDM-Q-9 should only be applied in the case of preference-sensitive decisions – i.e. when there are several treatment possibilities for a particular disease.

The SDM-Q-9 was developed in a theory-driven manner and measures the extent to which patients are involved in the process of decision-making from the perspective of the patients. The revised 9-item version and a short description including quality criteria and hints for evaluation and interpretation can be found in the article PEF-FB-9 - Fragebogen zur Partizipativen Entscheidungsfindung (revidierte 9-Item-Fassung) [SDM-Q-9 – Questionnaire on Shared Decision-Making (revised 9-item version] by Scholl I, Kriston L and Härter M. Klinische Diagnostik und Evaluation. 2011 (4) 46-49.

A more detailed, English-language article on the SDM-Q-9 can be found in: The 9-item Shared Decision Making Questionnaire (SDM-Q-9). Development and psychometric properties in a primary care sample by Kriston L, Scholl I, Hölzel L, Simon D, Loh A and Härter M. Patient Education and Counseling. 2010 (80) 94-99.

If you have any questions, please send an e-mail to Isabelle Scholl.

The questionnaire: SDM-Q-9


The 9-item Shared Decision Making Questionnaire – physician version (SDM-Q-Doc)

The SDM-Q-Doc is an adapted version of the SDM-Q-9, which measures the degree of patient involvement in a physician consultation from the perspective of the physician. Development and psychometric properties of the Shared Decision Making Questionnaire--physician version (SDM-Q-Doc). Scholl I, Kriston L, Dirmaier J, Buchholz A, Härter M. Patient Educ Couns. 2012 Aug;88(2):284-90. doi: 10.1016/j.pec.2012.03.005. Epub 2012 Apr 3.

If you have any questions, please send an e-mail to Isabelle Scholl.

The questionnaire: SDM_Q_Doc


The Autonomy Preference Index (API-Dm)

Die deutsche modifizierte Fassung des Autonomie-Präferenz-Index (API-Dm) [The German modified version of the Autonomy Preference Index (API-Dm)] Simon D, Kriston L and Härter M. (2011)  Klin. Diagnositk u. Evaluation, 4Jg., 5-14.


The Autonomy Preference Index (API) was developed to measure patient preferences regarding information and involvement in medical decisions. The original English version consists of 23 items, which can be rated from 0 (“strongly disagree”) to 4 (“strongly agree”). The information preference is measured on the basis of eight statements. The measurement of the participation preference ensues through a total of 15 items. Of these, six items measure the general participation preference and nine questions assess the participation preference in terms of diseases of differing severity (case vignettes). The internal consistency of the API lies at .82 for each of the two subscales. The test-retest reliability amounts to .84 for the subscale on participation preference and .83 for the subscale on information preference.

A German translation of the API without case vignettes was applied in the research project “The patient as partner in the medical decision-making process”, funded by the German Federal Ministry of Health. Construct validity was checked with the aid of confirmatory factor analysis in a patient sample spanning across different indications (n=1592). On the basis of the fit indices, two items on participation preference and one item on information preference were removed. The German modified version (API-Dm) resulted in improved fit indices. Due to methodological limitations of the validation study, further psychometric tests of the API-Dm are recommended.


Preparation for Decision-Making Scale (PDMS-D)

Die Preparation for Decision-Making Scale in deutscher Sprache (PDMS-D) – Faktorielle und konkurrente Validität in einer Onlinestichprobe von Personen mit Kreuzschmerz oder Depression.

[The Preparation for Decision-Making Scale in the German language (PDMS-D) – Factorial and concurrent validity in an online sample of persons with lower back pain or depression].


The aim of the current investigation was to check factorial and concurrent validity as well as the reliability of the Preparation for Decision Making Scale in the German language (PDMS-D). In a randomised, controlled study on the evaluation of a web-based decision aid, study participants with depression and/or lower back pain, filled in, among other things, the PDMS-D directly following the decision aid. Data from 572 study participants were included in the current investigation. Confirmatory factor analyses resulted in a two-dimensional factor structure. Moreover, significant, low to high correlations with construct-related variables were shown (decision conflict, acceptance, knowledge) and low, non-significant correlations with construct-unrelated and control variables (quality of life, age, sex). The results of this study support the reliability and concurrent validity of the German-language PDMS-D, although the factor structure points to conceptual differences from the English-language PDMS-D: Instead of one dimension for decision preparation, the two dimensions preparation for the decision and preparation for the physician consultation are found. Application of the PDMS-D can be recommended for evaluating decision aids.



Fragebogen zur Zufriedenheit in der ambulanten Versorgung – Schwerpunkt Patientenbeteiligung (ZAPA). [Questionnaire on satisfaction in outpatient care – Focus on patient participation (ZAPA)] Scholl I, Hölzel L, Härter M, Dierks ML, Bitzer EM, Kriston K.(2011). Klinische Diagnostik und Evaluation 4Jg. 50–62.


The goal of this study was to develop and psychometrically evaluate a short questionnaire (four items) for measuring patient satisfaction in outpatient medical care under consideration of the concept of patient participation. To this aim, two items of an existing instrument were used (Questionnaire on Satisfaction in Outpatient Care – Quality from the patients’ perspective – ZAP), and two new items were generated. With the new instrument (ZAPA), data were gathered from a sample of 2450 patients. The dimensional structure was determined by means of factor analysis. In addition, reliability measures as well as descriptive item parameters were calculated. Moreover, construct validity was checked. The ZAPA shows a one-dimensional structure. A high internal consistency as well as high discriminatory powers point to a high reliability of the questionnaire. Completion rates of over 94% demonstrate a good acceptance of the instrument. Furthermore, there are indications of construct validity. On the whole, the ZAPA shows good psychometric properties. Due to its brevity, it is suitable for use in studies to measure patient satisfaction in outpatient care settings.

 If you have any questions, please send an e-mail to Isabelle Scholl.

Other measures

Several other measures have been developed/translated and psychometrically tested over the last years. Short descriptions of these publications are given below..

If you have any questions, please send an e-mail to Levente Kriston.

Four Habits Coding Scheme – German version

The German version of the Four Habits Coding Scheme – association between physicians' communication and shared decision making skills in the medical encounter. Scholl I, Nicolai J, Pahlke S, Kriston L, Krupat E, Härter M. (2014) Patient Education and Counseling, 94: 224-229.


Objective: To translate a measure of physicians' communication skills, the Four Habits Coding Scheme (4HCS), into German, to examine its psychometric properties, and to analyze its association with the OPTION Scale, which assesses physicians' shared decision making (SDM) behavior.

Methods: We performed a secondary data analysis of 67 audio-recorded medical consultations. Reliability, internal consistency, and factorial validity of the translated 4HCS were analyzed. The association with the OPTION Scale was examined using correlation and linear regression.

Results: Testing of reliability revealed intraclass correlation coefficients above .70. Results regarding internal consistency and factorial validity were inconclusive. The correlations between the OPTION score and the four dimensions of the 4HCS were .04 (p=.782), -.14 (p=.303), -.15 (p=.279) and .55 (p<.001), respectively. In multiple regression the four dimensions of the 4HCS explained substantial amount of variation in the OPTION scores (R(2)=.42, P<.001).

Conclusion: The measure showed good observer reliability, however further testing is necessary. Due to the strong interrelation of both measures, SDM should be seen in the context of broader communication skills.

Practice implications: The 4HCS can be used in research and medical education. Further studies are necessary that investigate SDM within the context of communication skills.

Decisional Conflict Scale – German version (DCS-D)

German-language version of Decisional Conflict Scale (DCS-D). Dimensional structure in a sample of family physician patients. Buchholz A, Hölzel L, Kriston L, Simon D, Härter M (2011). Klinische Diagnostik und Evaluation, 4: 15-30.


The Decisional Conflict Scale (DCS) has been developed as an outcome assessment for the evaluation of decision-support systems. It captures uncertainty about which course of action to take facing a medical decision. While the DCS has been widely used, studies investigating its psychometric properties are scarce. There is no published data on the German DCS available. Aim of this study was to investigate psychometric properties of a German version of the DCS. For this study, data have been gathered in a large postal survey investigating the effects of integrated primary health care. Data of 1286 respondents were included in the analyses. Confirmatory factor analyses revealed the five-dimensional structure as suggested by the original authors as superior to other investigated factorial structures. Furthermore, the internal consistency of the five subscales was found to be high. This study corroborates the factorial validity and reliability of the German DCS.

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