The goals of medical communication are optimal health and improving quality of life. Medical communication has six functions:

1. Fostering the relationship
   This has the goal of achieving an effective relationship.
2. Gathering information
   This has the goal of having an adequate diagnosis and interpretation of the symptoms.
3. Providing information
   This has the goal of having a well-informed patient.
4. Decision making
   This has the goal of reaching an effective and preferred decision.
5. Enabling disease and treatment-related behaviour
   This has the goal of having adequate and feasible disease- and treatment-related patient behaviour.
6. Responding to emotions
   This has the goal of having effective communication and providing support for the patient.

The communication functions influence proximal outcomes (e.g. trust), which, in turn, influences intermediate outcomes (e.g. commitment to treatment). The intermediate outcomes influence the health outcomes. The communication functions also directly influence health outcomes.

Bird’s model of medical communication states that a medical interview has the functions of gathering biological and psychosocial data (1), responding to the patient’s emotions (2) and educating patients and influencing their behaviour (3). The three functions model states that the three functions of a medical interview are the need to determine and monitor the nature of the health problem (1), the need to develop, maintain and conclude the therapeutic relationship (2) and the need to carry out patient education and implementation of treatment plans (3). The framework for patient-centred communication states that the functions of a medical interview are fostering relationships (1), information exchange (2), making decisions (3), enabling self-management (4), responding to emotions (5) and managing uncertainty (6).

Trust, in physicians, refers to the optimistic acceptance of a vulnerable situation in which the patient believes the physician to care for his interests. It is a psychological need because of vulnerability and unavoidable in severe disease. It is associated with risk. There are several dimensions of trust:

1. Competence
   This refers to avoiding mistakes and producing best achievable results.
2. Honesty
   This refers to telling the truth and avoiding intentional falsehoods.
3. Fidelity
   This refers to putting the patient’s interests first.
4. Confidentiality
   This refers to telling the truth and avoiding intentional falsehoods.
5. Caring
   This refers to the time, attention and sympathy devoted to the patient.

There are several layers of interpersonal trust:

1. Dispositional trust
   This refers to trust related to dispositions (e.g. personality; coping style; attachment style).
2. Learned trust
   This refers to a general tendency to trust another individual which is learned through different methods.
3. Situational trust
   This refers to trust dependent on situational cues.

Non-verbally expressed uncertainty led to reduced trust. There is stronger overall trust for older patients. Patient’s trust is enhanced by emphasizing medical competence (1), honesty (2) and caring communication (3). Physicians can strengthen their patient’s trust in them with minimal adjustments to their communication. Physician’s communication can enhance recall and can reduce patient’s psychophysiological response. However, the mechanisms of this remain unclear.

Participation refers to action, involvement and influence within the health-care environment. Patient-participation consists of seeking health-related information (1), being involved in medical decision making (2) and interacting with providers in a way that narrows the knowledge and power gap between provider and patient (3). Patients must express their needs (1), concerns (2), preferences (3), ideas about health (4) and expectation for care (5).

Asking questions (1), expression of concern (2), assertiveness (3) and health narratives (4) are types of speech that influence events of consultation and the provider’s behaviour. The health narrative provides important contextual information about the patient’s health status (1), needs (2), behaviour (3), beliefs (4) and values (5).

Active patient participation can improve treatment outcomes because patients receive care tailored to their unique needs (1), it may enhance adherence to treatment programmes (2) and may enhance a patient’s perception of control over health (3).

Shared decision making refers to a conversation between physician and patient in which they mutually exchange information and considerations to reach a treatment decision that best fits the unique patient.

Shared decision making should be used when:

• There is more than one reasonable approach available to manage the patient’s situation.
• The approaches differ in ways that matter to the patient.
• There is scientific uncertainty regarding the approaches (e.g. no evidence).
• The stopping of treatment is also an option.

There are four steps to shared decision making:

1. Setting the shared decision making agenda.
2. Informing about the options.
3. Exploring the patient’s values and support preference construction.
4. Making or deferring a decision in agreement.

Training physicians improves the observed and reported patient shared decision making. Providing the patients with a preparatory communication aid did not improve this. In order to maintain the effects, the training should be incorporated in the physician’s education and should be repeated over time.

Effective decisions are decisions for which there is sufficient evidence on benefit-harm ratios and the harms are small compared to the benefits. In preference-sensitive decisions, there is no optimal strategy. When communicating the benefits and harms of treatment, a physician should not make it normative.