Measuring shared decision making in the consultation: A comparison of the OPTION and Informed Decision Making instruments

Abstract

Objective

To investigate the applied and conceptual relationship between two measures of shared decision making using the OPTION instrument developed in Wales and the Informed Decision Making instrument developed in Seattle, USA using audio-taped consultation data from a UK general practice population.

Methods

Twelve general practitioners were recruited from 6 general practices in the southwest of England. One hundred twenty-three GP-patient consultations were audio-recorded. Audiotapes were sent off to, and rated by, respective experts in the use of the OPTION and the Informed Decision Making instruments.

Results

Compared to earlier work using the Informed Decision Making tool, consultations in this sample were shorter, had fewer decisions and tended to have a greater number of elements present. Similar to previous research using the OPTION, values using the OPTION instrument were low with two items, giving the patient opportunities to ask questions and checking patient understanding, exhibiting the most variability. Using a ‘key’ decision in each consultation as the basis for comparison, the Informed Decision Making score was not related to the overall OPTION score (Spearman's rho = 0.14, p = 0.13). Both instruments also predicted different ‘best’ and ‘worst’ doctors. Using a Bland–Altman plot for assessing agreement, the mean difference between the two measures was 1.11 (CI 0.66–1.56) and the limits of agreement were −3.94 to 6.16. There were several elements between the two instruments that appeared conceptually similar and correlations for these were generally higher. These were: discussing alternatives or options (Spearman's rho = 0.35, p = 0.0001), discussion of the patient's role in decision making (Spearman's rho = 0.23, p = 0.012), discussion of the pros/cons of the alternatives (Spearman's rho = 0.20, p = 0.024) and assessment of the patient's understanding (Spearman's rho = 0.19, p = 0.03).

Conclusion

Measures of shared decision making are helpful in identifying those shared decision making skills which may be problematic or difficult to integrate into practice and provide a tool by which the development of skills can be assessed over time. Research may implicitly place undue value on those aspects of shared decision making which are most easily measured.

Practice implications

Shared decision making tools are a useful way of capturing the presence or absence of specific shared decision making skills and changes in skills acquisition over time. However there may be limits in the extent to which the concept of shared decision making can be measured and that more easily measured skills will be emphasised to the detriment of other important shared decision making skills.

Introduction

There is an ever increasing range of patient-centred instruments to measure communication and consultation skills in the health professional–patient encounter [1], [2]. These range from history-taking [3], non-verbal behaviour [4], empathic processes [5], [6], or the skills needed to demonstrate evidence-based patient choice [7]. Some instruments are more appropriate for use in teaching where the ‘findings’ are used formatively to improve communication and consultations skills [5], [8]. Other observational instruments focus on interaction analysis; coding phrases or utterances of speech [9], [10], [11]. To develop an instrument which has good internal and external validity, is reliable yet easy to use (e.g. minimal training requirements) and has wide acceptance and use amongst researchers and practitioners in shared decision making is a goal for any such instrument.

The common thread between tools is the aim to quantify aspects of human interaction in order to judge ‘good’ communication between (most commonly) doctor and patient. Yet there is a broad spectrum in how different instruments have been operationalised. There may be a conceptual overlap between individual items on different instruments without there being a complete overlap of items across the two instruments as a whole. For example, in patient-completed measures, an item such as ‘the doctor seems interested in me as a person’ might overlap conceptually with ‘how much would you say that this doctor cares about you as a person?’ but the former is part of a rapport sub-scale on the Medical Interview Satisfaction Scale [12] while the latter is part of an understanding the whole person sub-scale on the Patient Perception of Patient Centredness scale [13], [14]. There are also differences in terms of depth of individual elements on a particular tool. Some items focus on discrete, observable skills (competencies) such as ‘avoids directive or leading questions’ while other items are broad competences (outputs) such as ‘involves patient in deciding upon a plan’ which might include several competencies within it [15]. The other key issue in the development of instruments is the perspective adopted for the rating of consultations: patient completed instruments, observer-rated instruments or health professional completed instruments. Different instruments from different perspectives will potentially lead to conflicting views as to what constitutes a ‘good’ consultation. This paper will explicitly focus on observer-rated instruments.

Shared decision making can be considered an important aspect of patient centredness [16] and the consultation process. Attempts have been made to develop a core definition of shared decision making [17] in order to develop consistent measures which can be related to patient outcome. The most widely accepted model of shared decision making draws upon the work of Charles et al. [18], [19] most recently tailored to fit the context of general practice [20]. As originally devised, this model describes shared decision making as having four characteristics: (1) both the doctor and patient are involved in the treatment decision-making process; (2) both share information with each other; (3) both take steps to participate in the decision-making process by expressing treatment preferences and (4) both the doctor and patient agree on the treatment to implement. As constructed, shared decision making has elements which overlap with the tools described above such as exploring the patient's reasons for attending, adopting a bio-psychosocial perspective, giving information and eliciting patient concerns. There are two observer-rated tools, the observing patient involvement [OPTION] instrument developed in Wales and the Informed Decision Making [IDM] instrument development in California, which take an explicitly shared decision making perspective.

The OPTION scale was developed from a skills framework and consists of a set of competences [21] which include:

• problem definition;

• explaining legitimate choices;

• portraying options and communicating risk;

• conducting the decision process or its deferment.

The psychometric properties of this scale have been explored and it has undergone extensive reliability testing [22], [23]. Early use of Likert scales to rate competences have evolved to magnitude scales rated from ‘0’ to ‘4’ and improved OPTION's reliability [23]. More recently OPTION has been used in a cluster randomised controlled trial to investigate the effects of interventions to improve doctors’ skills in shared decision making or in their use risk communication aids [24].

The Informed Decision Making [IDM] tool identified both the shared decision making and informed consent paradigms as relevant to its conceptual development. The authors initially identified six elements in the IDM model, drawn from the bioethics literature:

• discussion of the clinical issue and nature of the decision to be made;

• discussion of the alternatives;

• discussion of the pros and cons of the alternatives;

• discussion of the uncertainties associated with the decision;

• assessment of the patient's understanding;

• asking the patient to express a preference [25].

This research was followed up with a large study of 1057 doctor–patient interactions among 124 doctors [26]. This later study added the additional element of ‘discussion of the patient's role in decision making’ and found that only 9% of decisions met their definition for informed decision making.

In a review of patient–doctor communication assessment instruments, 44 instruments were examined [1]. Assessment tools included those using real-time assessment by an observer, those using standardised patients to assess communication skills, assessment with video or audio taped interactions and measures using self report by doctors or patients. The authors were critical of some measures which had been used solely by their developers and for their lack of robust reliability and validity testing [1]. There have been a few studies comparing across instruments but poor concurrent validity amongst instruments has been found [27], [28], [29]. A notable exception is the Roter Interaction Analysis System (RIAS) which has been shown to have good predictive validity with other instruments [30].

One solution to the growth of communication instruments is to develop a new instrument which involves several research groups, is tested rigorously for validity and reliability and is used widely. Another approach is to undertake comparative work between two or more instruments. Two instruments, the OPTION instrument developed in Wales and the Informed Decision Making instrument developed in Seattle, USA, were compared. The reasons for comparing these two particular instruments are (a) both instruments have an explicit focus developed from a theoretical perspective of involving patients in healthcare decision making; (b) both assume a chronology for the consultation for the rating process; (c) the Informed Decision Making tool had the highest number of stages or competences in common with Elwyn's stages identified with his tool [21] and (d) the Informed Decision Making tool was identified by Elwyn as the instrument most directly comparable with his instrument [22].

This was a feasibility study to explore in an undifferentiated general practice population, the relationship between the OPTION and Informed Decision Making instruments. For brevity, the term ‘shared decision making’ will include both the shared decision making and Informed Decision Making approaches.