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Cochrane Database of Systematic Reviews Protocol - Intervention

Contracts between patients and healthcare practitioners for improving patients' adherence to treatment, prevention and health promotion activities

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Abstract

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of contracts between patients and healthcare practitioners on (1) patients' adherence to treatment, prevention and health promotion activities, and (2) patients' health status.

Background

For any effective intervention to reach its desired outcome, participants need to take advantage of the advice, treatments and other actions offered by healthcare practitioners. A number of good studies and systematic reviews have evaluated interventions to improve patients' adherence to treatments. One that is used widely is the formation of a contract between healthcare practitioners and participants. We examine here the use of contracts to improve adherence, paying attention to the type of relationship that develops between patients and healthcare practitioners.

Contracts are defined as a mutual agreement between two or more parties that something shall be done by one or both (OED 2003). As a behavioural strategy aiming at improving patients' adherence, contracts refer "to a process of specifying a set of rules regarding some behaviour of interest and formalising a commitment to adhere to them" (Dunbar 1979). They are referred to as simply contracts, behavioural contracts or contingency contracts. Contracts have been used in a wide range of circumstances such as smoking cessation, breast self‐examination, hypertension, diabetes, rheumatic diseases, tuberculosis, hepatitis, in renal patients, and in psychiatric conditions.

The following summarises the features of contracts when used as strategies to increase adherence:

  • Formalisation. Contracts are often written, but some examples exist of verbal contracts (Anderson 1982; Arnet 2000).

  • Parties. Contracts are most often established between patients and their physicians. There are examples of other parties being involved, such as nurses and patients (Boehm 1997), patients and selected partners from the household or the community (Keane 1984; Lierman 1994; Morisky 2001; Ossip‐Klein 1984), and even contracts with the patients themselves (a self‐commitment made explicit) (Brus 1998). We found one report of a tripartite contract: between the patient, the healthcare practitioner of a Pain Clinic and the Primary Care Physician (Fishman 2002).

  • Usually adults. Contracts primarily involve adult patients, although adolescents (Morisky 2001; Wysocki 1989) and children (Greenan‐Fowler 1987; Sherman 1991) have also been involved. The role of children is particularly delicate, since they are often in a triangular relationship with their carers and healthcare practitioners, and they have a special right to access appropriate information (Sanz 2003).

Contracts formalize the commitment of patients and/or healthcare practitioners to follow treatment, prevention or health promotion activities. These usually involve therapeutic activities (particularly adherence to prescribed drugs) but they also include: observance of appointments (Hayes 2000); lifestyle behaviours, such as smoking cessation (Resnikow 1997) and nutrition habits (Boehm 1997); and diagnostic actions, like breast self‐examination (Lierman 1994).

When contracts include a reward conditioned by the accomplishment of the contract clauses, they are referred to as contingency contracts: "a specifically negotiated agreement that provides for the delivery of positive consequences contingent on desirable behaviour" (Janz 1984). There are two main types of rewards (Christiensen‐S. 1985). 'Token economies', which were initially used as a behavioural therapy, are rewards from the healthcare practitioner in the form of tokens that can be exchanged for something of value (Hayes 2000; Wysocki 1989). Rewards may also involve the refund of a deposit ('deposit contract') (Chowdhury 1997; Molteni 1983; Paxton 1983). One study reported a self‐reward, where the patient states what s/he will do to reward him/herself (Neale 1991). Another study involved insurance refund policies based on measures of success of treatments (Harzer 2000). Neither contingencies nor penalties seem to take place, however, if healthcare practitioners do not respect their terms in the contracts.

Ethical issues arise when access to treatment may be dependent upon patients' behaviour as specified in a contract (Biller 1999). Contracts have not been used only as behavioural therapy, but also to support decisions on the appropriateness of a given treatment. For example, one study described how compliance with a behavioural contract was used as a criterion to identify individuals with the potential to maintain a transplanted organ capably (Cupples 2001). The circumstances in which a patient can make a rational and autonomous choice, in the context of contracting, is also worthy of ethical consideration (Biller 1999).

Concordance and the relationship model

Compliance or adherence has been defined as "the extent to which a person's behaviour (in terms of taking medications, following diets or executing lifestyle changes) coincides with medical or health advice" (Haynes 1979a). The increasing use of the term 'adherence' instead of 'compliance' is due to the latter's negative and authoritarian connotations. Adherence implies the patient's active choice in following medical recommendations rather than passive co‐operation in obedience to them (Evangelista 2000). However, adherence still is rooted in a medical model where patients are expected to do what healthcare practitioners tell them. In this review, we use the term adherence in its most restricted sense, to designate the extent to which something that has been implicitly or explicitly agreed between healthcare practitioners and patients, actually happens.

Concordance has emerged as a term that aims to reflect that patients/persons have self‐determination and control over what happens to them. Concordance means shared decision making and arriving at an agreement that respects patients' wishes and beliefs (Jones 2003). Healthcare practitioners may also find, for example, that difficulties experienced by chronically‐ill patients with their treatments may be minimised in the context of a concordant relationship (Townsend 2003).

Some contracts depend on a relationship model. In behavioural contracts, the healthcare practitioner perspective predominates. References to healthcare practitioners' obligations (like providing information or evidence‐based treatments) are generally missing. In the literature scrutinised so far, contracts do not seem to be based on a relationship marked by shared decision‐making, but instead place the responsibility of failing the terms of the contract on the patients' side. The literature around concordance is particularly relevant. With concordance, an essential component in a shared decision‐making model is that of mutual agreement (implicit or explicit) with the treatment decision (Charles 1997). This kind of agreement may indeed reinforce the mutual contribution of healthcare practitioners and patients to a successful treatment (Maher 2003). Furthermore, it has been argued that unless patients and doctors are collectively or jointly involved in the decision‐making process, sharing information and building up consensus, there is no basis for reaching an agreement on which a treatment can be implemented (Stevenson 2000). In a concordant consultation the patient and the healthcare professional participate as partners to reach that agreement (Cox 2002).

Impact on health

Low adherence may seriously compromise the effectiveness of therapeutic regimens. It has been reported that adherence may be as low as 10% in keeping appointments (number of appointments kept in relation to the total number of appointments scheduled) or between 40% and 60% in the case of long‐term medications (percentage of patients with presence of medications in body fluids or self‐assessed reporting of drugs intake) (Sackett 1979). Poor adherence to treatment regimens has been associated with a reduction of the treatment effectiveness, leading to worse health outcomes (Cleemput 2002; Gordis 1979). The WHO report on adherence documents worse outcomes associated with poor adherence for conditions like hypertension, type‐2 diabetes and depression (WHO 2003). Interestingly, however, a Canadian study suggested that adherence to guidelines for the treatment of patients with radiological‐confirmed pneumonia was associated with increased adverse events (Loeb 2001). There is some evidence that the costs involved in treating non‐adherent patients are greater than those involved in treating adherent ones (Cleemput 2002; Heinssen 1995). In the United Kingdom (UK), it was estimated that missed appointments resulted in an economic loss of 250 million pounds sterling per year (DPP 2003).

Advantages of Contracts

What are the potential advantages of contracts over other interventions seeking to improve adherence and concordance? First, they could allow for better replication if they are standardised and do not include extensive training or educational components. Contracts may be cheaper to implement than other combined or more complex interventions or even than supervised self‐administration of drugs (Keane 1984). Apart from that, contracts have shown cost savings related to an increase in adherence and the rationalisation of the care provided (Heinssen 1995). For patients/participants, provided that the interventions used are effective, the benefits include health gains, psychological comfort (Jones 2003) and a better understanding of what they are expected to do and why.

Evidence base for improving adherence

Haynes reviewed the factors associated with the level of adherence to therapeutic regimens (Haynes 1979b). The type of disease seems to play a secondary role, except in specific conditions; for example adherence tends to be lower in some psychiatric disorders such as depression. Organisational issues such as referral delays, waiting times and appointment schedules have a stronger influence on the level of patients' adherence. In relation to the features of the therapeutic regimens, low adherence has been almost constantly found in treatments of longer duration and involving several drugs. Socio‐economic barriers, side effects of treatment and denial of the illness have also been related to poor adherence (Mellins 1992). Finally, the interaction between patients and healthcare practitioners is decisively important in ensuring that what has been explicitly or implicitly agreed, actually takes place. Effective communication of usage instructions for drugs, and the clinician's understanding of patients' concerns about their problems or treatment preferences, have been associated with an increase in patients' adherence and willingness to participate (Hulka 1979).

Interventions to increase adherence may address organisational issues, the simplification of therapeutic regimens, the interface between the patient and the healthcare practitioner and patients' behaviour. Strategies to increase adherence to regimens have been systematically reviewed in general (Haynes 2003) and in relation to specific diseases, like tuberculosis (Volmink 2000; Volmink 2003), HIV/AIDS (Haddad 2003) or mental illness (Reda 2003), reporting the effects on patients' adherence and on other outcomes. These interventions tend to be complex. First, many different actors and activities may be involved. For example, educational interventions may involve physicians, other therapists, facilitators, educational materials, different schedules and structures of the sessions. Second, some interventions are a combination of different strategies (for example, patient instructions with visits to a specialist, or patient brochures with group sessions). This complexity makes it very difficult to know which are the key elements that may have an impact on patients' adherence or on the improvement of health outcomes. Results from these reviews indicate that some strategies or combination of strategies may improve adherence or health outcomes, but their effects are not very remarkable overall when compared with the effort they require (Haynes 2003).

While this review focuses on a single strategy (contracts) in the context of any health condition, several systematic reviews have assessed interventions to improve adherence or compliance in relation to specific conditions. Four of them included contracts. One was restricted to adherence to appointment keeping, and considered only randomised controlled trials written in English (Macharia 1992). Another assessed controlled studies, published in English language journals, of patients' adherence to therapeutic regimes (Roter 1998). Two other reviews were published in The Cochrane Library. One of them focused on tuberculosis (Volmink 2003) and the other considered adherence to prescribed (self‐administered) medications only (Haynes 2003). No systematic review has addressed contracts as a strategy to improve patients' adherence to any kind of treatment, prevention or health promotion activity, regardless of the setting and the condition or disease affecting the patients.

Objectives

To assess the effects of contracts between patients and healthcare practitioners on (1) patients' adherence to treatment, prevention and health promotion activities, and (2) patients' health status.

Methods

Criteria for considering studies for this review

Types of studies

Randomised controlled trials (RCTs), controlled before‐and‐after studies (CBAs) and interrupted time series (ITS) analyses.

Types of participants

Patients or their carers, of any gender and age, with any health condition and in any health setting. The term patient is used broadly to refer to any person undergoing diagnostic tests, or treatment, or participating in any health prevention or promotion initiatives.

Practitioners, including clinicians, nurses and any worker or service providing screening, diagnosis, therapeutics, rehabilitation, prevention or health promotion activities.

Types of interventions

Contracts concerning treatment, prevention and health promotion activities aimed at improving patients' adherence. Contracts include any verbal or written statement specifying at least one treatment, prevention or health promotion activity to be observed, and a commitment of adherence to it. Contracts may take place between healthcare practitioners or services and patients or their carers, between patients and their carers, or between patients themselves (self‐commitment). Contracts may relate to any diagnostic procedure, therapeutic regimen, rehabilitation measure, general health advice, referral instruction, or any other activity or combination of activities involved in the management of patients. Explicit rewards (like tokens, cash or social benefits) may or may not be present. Self‐management will be included, providing that self‐management appears to be supported by any form of contracting.

Control: any intervention (such as instruction, education, incentive or reminder) or combination of interventions not containing contracts, aimed at improving patients' adherence; or no intervention.

We will include studies of multifaceted interventions provided that a given modality of contracts is present in the intervention but not in the control group.

Types of outcome measures

It is likely that a wide variety of outcomes will be found. Outcomes will depend on the specific health conditions involved and on the setting in which the interventions are carried out.

Primary outcomes

  • Degree of patients' adherence or change in behaviour related to adherence (eg. patients' adherence to treatment regime or health promotion programme, consistency with agreed targets, attendance, participation numbers and rates, length/duration of participation; healthcare practitioners' adherence to agreed specifications).

Secondary outcomes

  • Patients' participation in the contractual process (such as inclusion of patients' values and preferences) and degree of shared decision making where alternative treatment options are present, assessed through qualitative statements or scales.

  • Outcomes of contingencies stated in the contracts, both for patients and for healthcare practitioners.

  • Patients' satisfaction with the contracting process, assessed either qualitatively or through scales. This includes satisfaction with the level of knowledge about the healthcare process, reduction in the level of distress and other psychological outcomes reported.

  • Healthcare practitioners' observance of contract terms and appraisal of the contracting process.

  • Health status measures: all outcomes consistent with, or relevant to, the aims/specifications of contracts, eg. for treatment, prevention or health promotion, including mortality and morbidity outcomes, improvement in the control of chronic conditions and relief of symptoms.

  • Harms associated with adhering to proposed treatment or health promotion activity, eg. reported side effects, defaulted treatment, difficulties associated with maintaining treatment or health promotion activities.

  • Costs or savings incurred by patients, healthcare practitioners, services or other institutions (eg. insurance companies) derived from adherence or non‐adherence to healthcare activities.

  • Ethical issues, such as denial or deferral of treatment.

Search methods for identification of studies

We will seek studies in any language regardless of their publication status (published, unpublished, in press and in progress).

We will search the Cochrane Consumers and Communication Review Group specialised register for relevant trials. Full details of the Cochrane Consumers and Communication Review Group methods, and the journals hand searched, are published in The Cochrane Library in the section on Collaborative Review Groups.

We will search the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library (issue 1, 2004). We will also search the following electronic databases using specific search terms in combination with the search strategy for identifying trials, as detailed in the Cochrane Reviewers' Handbook (Clarke 2002), and also the strategies for identifying CBA and ITS studies.

(1) MEDLINE (from 1966 to present)
(2) EMBASE (from 1980 to present)
(3) PsycINFO (from 1966 to present)
(4) CINAHL (from 1982 to present)
(5) Dissertation Abstracts. A: Humanities and Social Sciences (from 1966 to present)
(6) Sociological Abstracts (from 1963 to present)
(7) UK National Research Register (from 2000 to present)
(8) C2‐SPECTR, Campbell Collaboration (from 1950 to present)

We will search the reference lists of retrieved studies, and contact authors of existing reviewers on patients' adherence, for further references and details of meetings and conferences. The full search strategy for MEDLINE (Ovid) is as follows:

1 (contract or contracts or contracting).tw.
2 (agreement or agreements).tw.
3 (concord$ or negotiat$).tw.
4 (goal$ adj setting).tw.
5 or/1‐4
6 patient compliance/
7 (compliance or comply or complying or complied).tw.
8 (adherence or adher or adhering or adhered).tw.
9 or/6‐8
10 5 and 9
11 exp patient care planning/
12 (care plan$ or case plan$).tw.
13 case management.tw.
14 or/11‐13
15 5 and 14
16 exp decision making/
17 (information adj3 shar$).tw.
18 exp professional patient relations/
19 exp consumer participation/
20 informed consent/
21 partnership.tw.
22 or/16‐21
23 5 and 22
24 (behavioral adj3 contract$3).tw.
25 (behavioural adj3 contract$3).tw.
26 contingency contract$3.tw.
27 (contingent adj3 (contract$3 or intervention$ or reinforcement)).tw.
28 participation deposit$1.tw.
29 ((refund$or reward$ or incentive$ or penalt$ or punish$) adj5 contingent).tw.
30 ((refund$ or reward$ or incentive$ or penalt$ or punish$) adj5 (contract$ or agree$ or
concord$)).tw.
31 monetary deposit.tw.
32 ((monetary or payment$ or voucher$ or token$) adj3 contingent).tw.
33 or/24‐32
34 10 or 15 or 23 or 33
35 randomized controlled trial.pt.
36 controlled clinical trial.pt.
37 randomized controlled trials.sh.
38 random allocation.sh.
39 double blind method.sh.
40 single blind method.sh.
41 or/35‐40
42 animal/ not (human/ and animal/)
43 41 not 42
44 clinical trial.pt.
45 exp clinical trials/
46 (clin$ adj25 trial$).ti,ab.
47 ((singl$ or doubl$ or trebl$ or tripl$) adj25 (blind$ or mask$)).ti,ab.
48 placebos.sh
49 placebo$.ti,ab
50 random$.ti,ab.
51 research design.sh.
52 or/44‐51
53 52 not 42
54 43 or 53
55 34 and 54
56 cohort studies/ or cohort.tw.
57 (time adj series).tw.
58 (pre test or pretest or (post test or posttest)).tw.
59 or/56‐58
60 34 and 59
61 55 or 60

Data collection and analysis

Study selection

From the search results, we will assess the titles of potentially‐relevant studies. Where a study cannot be excluded on the basis of the title alone, we will obtain abstracts or full papers (where abstracts are not available). We will then obtain the full text of those studies deemed relevant by either reviewer. Potentially‐relevant papers will be independently assessed for inclusion by two reviewers against the review's inclusion criteria. Disagreements will be resolved through discussion and, if an agreement is not reached, referred to a third party. Reports will be scrutinised for multiple publication. We will exclude studies that do not meet the inclusion criteria and we will give the reason in the 'Characteristics of excluded studies'.

Assessment of methodological quality

Two reviewers will assess independently the quality of studies following the guidelines of the EPOC group (Alderson 2003). This process will not be blind in relation to the authors, their institutions and journals. The quality of RCTs will be assessed in terms of generation of allocation sequence, allocation concealment, blinding and loss to follow up. For CBAs we will consider whether baseline measurements were made, baseline characteristics of both groups were similar, the assessment of primary outcomes was blind, the control group did not receive the intervention, primary outcome measures were reliable and losses were less than 20%. For ITS we will consider whether the intervention was independent of other changes, there were sufficient data points to enable statistical inference, a formal test for trend was done, the sources and methods of data collection were the same before and after the intervention, the assessment of the primary outcome was blind, losses were less than 20% and primary outcome measures were reliable.

We will use a form to guide the assessment of methodological quality, and will classify each quality component as 'adequate', 'inadequate' or 'unclear'. All studies will be included and presented by type of study and quality level. If essential information to judge quality is missing, we will attempt to contact the author(s). Disagreement will be resolved by discussion or by seeking the advice of a third reviewer.

Data Extraction

We will extract data about the study design, methods, participants, interventions, co‐interventions and outcomes. Data extracted to describe the modality of contracts will include: formalisation and duration of contracts; parties; treatment, prevention and health promotion activities involved; contingencies; relationship model; inclusion of personal values and preferences; and ethical considerations taken into account. We will also extract data on patients' socio‐economic status, morbidity, co‐morbidity and severity of disease.

We will extract the following data on outcomes (for all parties, eg. for children and parents): measures of adherence to therapeutic regimens and use of services; adherence of healthcare practitioners to the terms of the contracts; penalties and rewards; quantitative measures or qualitative data describing the level of shared decision making; measures of satisfaction with the process; expectations and psychological distress; healthcare practitioners' understanding and behaviour in relation to contracts; health status data, such as improvement in clinical parameters or prognosis; cost information, detailing where possible the way costs have been estimated; and data on harms derived from the adherence or lack of adherence to treatment/s.

Two reviewers will extract data independently, and disagreement will be resolved by discussion or by seeking the advice of a third reviewer.

Where no intention‐to‐treat (ITT) analysis has been carried out, we will try to extract data to do it. Percentage loss to follow up will be presented as reported, or calculated if the number of selected individuals does not match the number of individuals whose data has been analysed. For binary outcomes we will record the number of participants experiencing the event in each group and calculate the odds ratios. For continuous outcomes we will extract the arithmetic means and standard deviations (SD). Percentages of change (in CBA studies) and measures of trend (in ITS studies) will be calculated if possible. Summaries of data will be presented in the results table.

Data Analysis

Studies will be stratified by study design, by quality and then by the level of formalisation of contracts. The table will include details of the outcome(s). A summary indicator of adherence and health outcomes will be produced (does good, no effect, does harm).

We anticipate substantial differences in the type of outcomes and in the way they will be reported. Therefore, we do not foresee the application of meta‐analysis methods. However, if studies can be grouped, meta‐analysis will be considered. Options that will be explored include grouping by health status outcomes, the presence and type of contingencies, the degree of shared decision making and the type of healthcare activity (treatment, rehabilitation, prevention or health promotion).

Consumer participation

Given that this review is not limited to any particular condition, we have sought input from consumers or patients ideally not restricted to a single disease group and, possibly, with experience or involvement in issues related to the relationship between patients and healthcare practitioners. Consumer participation will be ensured in the protocol stage, in the development of the review and in its updates.

The protocol, together with a user‐friendly questionnaire in electronic format to guide the process, was sent to a number of consumers for comment. Feedback was received from the following people and institutions: a social sciences and gender specialist working as a Community Research and Training Consultant, who is familiar with consumers' points of view (the Gender and Health Group, Liverpool School of Tropical Medicine, Liverpool, UK), and the Director of Developing Patient Partnerships (London, UK).

The Cochrane Consumers and Communication Review Group involved two other consumers as external peer‐reviewers of the protocol. Suggestions from consumers have been incorporated into the protocol as much as possible.