From Volume 10, Issue 1, January 2017 | Pages 8-14
Discontinued and abandoned cases are an undesirable outcome of orthodontic treatment. The first of this 2-part series will detail the different factors that play a role in this phenomenon. The second paper will describe a study that attempts to identify specific factors that are implicated in discontinued treatment within a specialist orthodontic practice.
Orthodontic treatment, in common with other medical interventions, carries with it a number of potential negative consequences which must be balanced against the benefits that treatment offers. Discontinued and abandoned cases are those that are terminated prematurely, before the intended outcome of treatment has been achieved. Discontinuation rates (DR) of up to 40% have been previously reported,1 but in the UK they generally range from 8–14% (Table 1). A study of UK-based orthodontic consultants showed a DR of 9.2%,2 with a more recent audit of early debonded cases reporting a DR of 11.2%.3 Older papers on NHS services show DRs of between 12% and 20%.4,5 NHS general and community services have shown DRs of 13.1% and 12.5%, respectively.6 Outside the UK, Swedish papers report DRs of between 4% and 15%;7,8 German studies show DRs ranging from 10–20%.9,10
| Discontinuation Rate | Year | Author | |
|---|---|---|---|
| NHS Primary Care Orthodontic Services England and Wales | 8.4% | 2013 | BSA–NHS |
| NHS Primary Care Orthodontic Services England and Wales | 10% | 2014 | BSA–NHS |
| UK-based Orthodontic Consultants | 9.2% | 1995 | Willmot et al2 |
| UK-based Orthodontic Consultants | 11.2% | 2005 | McMullan3 |
| NHS Hospital Orthodontic Department | 12.8% | 1989 | Murray5 |
| NHS Community Dental Service | 12.5% | 1991 | Eaton et al6 |
| NHS General Dental Service | 13.1% | 1991 | Eaton et al6 |
The most recent NHS figures for England and Wales give discontinuation rates of 10% and 9% for 2014 and 2015, respectively. This failure rate of around 1 in 10 cases is a considerable drain of publicly funded resources and an inefficient use of clinical time.
A lack of patient compliance lies at the heart of this phenomenon, and it can have serious consequences for the dentition (Figure 1). The seminal definition of compliance was given by Haynes: ’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’.11 However, compliance implies a passive patient role, therefore adherence is now regarded as a more appropriate term; adherence describes a collaborative relationship between patient and clinician, with both being actively involved in the execution of treatment. The level of cooperation varies greatly between patients and it becomes especially difficult to gauge during adolescence. At this stage of development the patient is experiencing a potential maelstrom of emotions that are associated with the development of values and goal-orientated behaviours; there is also a change from parental to peer influences. For orthodontists, this compounds the difficulty of patient management.
Patient adherence is a complex subject that involves psychological and behavioural considerations as well as patient and treatment related factors. Numerous factors have been studied and considered in an attempt to determine what may or may not contribute to a patient's lack of adherence to treatment (Table 2).
| Type of Appliance | Discontinuation is much more likely with removable appliances compared with those that are fixed. |
| Missed Appointments | A poor attendance record is associated with poor adherence. |
| Age | Pre-adolescents are generally more adherent, especially with functional appliances. Parental influence diminishes with increasing age. |
| Clinician-Patient Communication | A positive rapport between clinician and patient and an empathetic approach in dealing with the patient will improve adherence. |
| Clinician Factors | Dentists may refer inappropriate candidates for orthodontic treatment: patients with a greater perception of their malocclusion are more likely to be adherent. |
| Gender | Stronger evidence to suggest females are more adherent than male patients, but evidence is mixed. |
| Oral Hygiene | Possibly linked to poor adherence but evidence is weak. |
| Treatment Length | Adherence can be challenged if treatment is prolonged. Patient burnout may compromise final result. |
| Socio-Economic Status | Inconclusive evidence. Suggested that a low socio-economic status is a possible risk of poor adherence but not a predictor of it. |
| Bracket Failures | Associated with poor adherence but not a predictor of discontinued treatment |
| IOTN and Treatment Complexity | Evidence suggests complexity of treatment and IOTN have little influence on adherence. Patient's perception of aesthetics is more significant. |
| Personality Type | Not thought to be predictive of patient adherence. |
Patients that adhere to treatment protocol are generally under 14 years of age, enthusiastic, outgoing, energetic, self-controlled, hard-working, trusting, obliging and determined to do well. In contrast, non-cooperative patients are generally over 14 years old, intelligent, independent, aloof, often nervous, impatient, individualistic, easy-going, intolerant of prolonged effort and disregard the wishes of others.12 Although personality traits have been studied in an attempt to categorize adherent and non-adherent patients, they are not thought to be predictive of behaviour.
Historically, females have been considered to be more motivated and adherent,13,14 but the evidence for this is mixed. Several papers suggest no difference in adherence between the sexes.5,15 A recent study has suggested females are more likely to adhere to wearing removable appliances (RAs).16 Bracket failures have been reported to be more frequent in male patients,17 but no gender difference was found in another study.18
Much of the evidence suggests that younger patients are more likely to be adherent with treatment,19 and this is certainly true in the case of adherence to functional appliance therapy.20,21 Pre-adolescents have a different psychological make-up from adolescents, making them more likely to seek the approval of adult role models and thus making them more amenable to treatment. The importance of parental attitudes and their effect on potential patient adherence is well documented.22 In general, the older adolescent patient is more influenced by peer control, with parental control being diminished.23
The link between poor oral hygiene (OH) and the risk of developing demineralization is widely acknowledged and sub-optimal OH is recognized as an indicator of poor adherence to orthodontic treatment.3,24 However, one study from the 1980s has suggested that poor OH doesn't necessarily equate to poor appliance maintenance.25
When considering occlusal indices and the classification of the occlusion, most published work indicates that potential adherence is more likely to be determined by patients’ own perception of their treatment need as opposed to a clinician's objective view of the dental health implications of a malocclusion. There is considerable evidence that patients' Index of Orthodontic Treatment Need (IOTN) is not necessarily related to their own perception of treatment need and to the subsequent uptake of orthodontic treatment.26 A patient's self-perceived need for treatment is more likely to show a stronger correlation with the aesthetic score rather than the dental component of IOTN.27,28
Studies have failed to show a conclusive association between socio-economic status (SES) and patient adherence.29 It has been suggested that SES is a risk of non-adherence but is not a predictor of it.30 Evidence also suggests that SES has a role to play in patients' desires and self-perceived need for treatment,31,32 which could affect their eventual adherence. However, the evidence is unclear on the exact effect of SES: some studies relate a higher SES to increased treatment demand33 and a low SES to reduced treatment uptake.34
It has been suggested that patients living in rural areas have less desire for treatment34 and this may impact on completion of treatment because of the travel costs involved.
Patients that fail to attend (FTA) for orthodontic appointments are associated with poor adherence and a higher propensity for discontinuing treatment.5,35 Trenouth conducted a study to investigate this specific association within a hospital orthodontic department which concluded that there was a statistically significant increase in the number of FTAs in patients whose treatment was abandoned.36
An appliance that is removable is, by definition, more likely to be associated with non-adherence because it can be easily removed by the patient.35 Of the few studies that test methods of monitoring patient adherence, most involve the use of timing devices and time-wear diaries in RAs37,38 and headgear (HG)39,40,41,42 HG has been commonly associated with non-adherence but interestingly, in one study, there was little difference in rates of adherence in HG and functional appliance (FnA) cases.43 Although headgear is becoming less used, the utilization of timing devices and wear time diaries still have potential in FnA, RA and other treatment regimens dependent on patient cooperation.
Appliances that have a detrimental effect on speech and swallowing can cause a lack of confidence in public, which will have a deleterious impact on patient adherence.44 FnAs put a high demand on patient adherence and can result in high failure rates of over 30%.45 Pain can also impact on adherence, with one study concluding that pain is reported more with FnA and FAs as opposed to RAs; the same study suggests that pain experience in the early stages of treatment is a good indicator for future treatment acceptance.46
Bracket failures are associated with poor appliance maintenance and hence poor patient adherence.13 Although bracket failure is associated with poor adherence, there does not appear to be any evidence to suggest that it can predict discontinued treatment.
The timing of the start of orthodontic treatment is significant. Treatment started in pre-adolescence has the advantage of a potentially more adherent patient.47 A recent systematic review confirms that there is no biological advantage in committing a patient to early treatment other than it reduces the chances of incisor trauma.48 A ‘burnout’ process has been described where a patient's enthusiasm, and hence adherence, can be seriously eroded as treatment length and the number of visits go beyond a stage where patients recognize significant improvements in their malocclusion.49 Poor patient cooperation is likely to increase treatment time.50 An extensive American study analysing the treatment outcome of patients in a graduate orthodontic training programme suggested that there was little evidence to support the continuation of prolonged treatment due to poor patient cooperation; it was more prudent to discontinue these cases early and accept a less than ideal result.51 A UK study of the patients of postgraduate students on a specialty training programme noted that the treatment outcome, as assessed by the PAR score, did not vary significantly in relation to treatment length,52 which supports the idea that prolonging treatment is not justified on the basis of achieving an improved outcome. The effects of this phenomenon can be lessened by appropriate communication between the clinician and patient, reinforcing the patient's understanding of treatment objectives with short term rewards.53
Poor candidates for orthodontic treatment may be referred inappropriately.54 Clinicians must appreciate patients' subjective opinion of the aesthetic appearance of their teeth as it is thought that those that are dissatisfied are more likely to comply with orthodontic treatment.55 The anterior facial profile has been indicated as having the strongest correlation with patients' psychosocial assessment of their malocclusion.56 Patients with a greater perception of the severity of their malocclusion and aesthetic needs are more likely to show adherence57 and are more likely to have a better comprehension of the risks and benefits of treatment.58
Studies have shown that the more experienced clinicians and specialist orthodontists are less likely to have cases that are discontinued compared with general practitioners.5,6,59
Evidence shows that communication skills are vital for improved adherence, with a good patient-dentist rapport and an open and honest approach being shown to be of importance in reinforcing adherence.57,60,61The mutual participation relationship describes a patient-clinician relationship that combines the thoughts and beliefs of the patient with the expertise and knowledge of the clinician. This approach is more likely to improve clinical outcomes compared to the active passive-relationship, where the clinician assumes total control over the passive patient or the guidance-cooperation relationship, where the clinician offers advice to a patient whose role is merely to comply.
Communication is a two-way process and is not so much about what is said, but what is heard. Communication is thought to involve three variables: tone, words and non-verbal body language. Non-verbal messages are of vital importance and will override any conflicting verbal communication, and the tone used in speech conveys the attitudes. There needs to be an emotional quality to the relationship. Poor adherence is linked to a brisk, business-like manner and a lack of response to non-verbal signals; an empathetic, friendly and interested approach plus the projection of calm confidence is preferred.62 A warm, caring clinician is more likely to induce better adherence63 and patient satisfaction.64
Reward systems may improve the behaviour of poorly adherent patients,65 with one paper suggesting short-term rewards and patients having confidence in their clinician can have a beneficial effect on improving adherence.53 A patient will be more likely to respond more positively to encouragement as opposed to criticism and chastisement.
Many studies that investigate adherence focus on factors that are not amenable to change, eg gender, family background and socioeconomic status. It's therefore of significance that a recent Cochrane review concluded that there was merit in pursuing a psychological approach to patient management in order to improve health-related behaviour.66 Social cognition is an individual's subjective assessment of his or her own environment as opposed to an objective view, and how these perceptions to external stimuli affect a person's response. Beliefs and attitudes have the potential to be changed through appropriate education and engagement with the patient.
Numerous social cognition models have been described and studied and these are summarized (Table 3). However, to date, owing to the complexity of the psychology of health-related behaviour, there exists no single theory that can explain individual variations of behaviour.
| Theory of Reasoned Action | Social norms influence behaviour and this is dependent on peer pressure, especially in small social groups. Family, friends and media (advertising, role models) are important. Individuals will perform a behaviour if they determine that it is beneficial and that people important to them would expect it of them. |
| The Health Belief Model | For patients to follow health advice they must believe that: |
| Health Locus of Control | A measure of patients' beliefs about their own level of control over what happens to them. They range from an internal locus of control (their own abilities and efforts provide total control) to an external locus of control (chance, fate, etc); the former are more likely to be adherent. |
| The Stages of Change Model | The concept that behaviour modification should be encouraged but any change is not final, merely part of an ongoing process. The defined stages are: |
This is a validated measure of patient adherence and was first described in the United States in the early 1980s.67 It was developed from the subjective view of trainee orthodontists and hospital-based orthodontists, and refined by the input of practice-based specialists. It has been utilized in subsequent studies that have examined adherence behaviour, but is not used as a practice-based tool during patient assessment. There are a number of other measures for patient adherence, some of which are similarly based on the subjective opinion of clinicians, and others on the opinion of clinicians and patients.
A number representing biological, physical, sociological and psychological parameters to give a measure of a person's sense of wellbeing.
A series of questions assessing the degree of patient concern or disadvantage to the arrangement of their teeth. The results are combined with the patient's subjective aesthetic component IOTN score to give the OASIS score.
Both have been tested to assess if they have a value in predicting potential adherence, but neither of them is thought to be a predictor of patient adherence.68
This is a 26-item self-report of psychometric measures concerning patients' attitudes towards their malocclusion and their desire for treatment. The two most important facets reflecting a desire for treatment were the wish for treatment by both the parent and child, plus the concern for treatment by both patient and parent. Two papers have discounted the value of this tool for predicting adherence.57,70
This measures the degree to which patients attribute responsibility for their malocclusion and subsequent orthodontic treatment modalities to internal or external influences. It is a 34-item Likert-type response inventory measuring self/internal control, external chance, external powerful others (parents), external powerful others (professionals). The literature to date shows that, due to the complexity of the nature of adherent behaviours, there remains no succinct and consistent measure of patient adherence and clinicians will use subjective and indirect methods to assess it.72
It is reasonable to assume that all patients that are accepted and consented for orthodontic treatment are done so with the goal of completing the course of treatment successfully. However, the rates of discontinued treatment have been shown to remain consistently at 8% or higher. Despite the existence of a wide range of literature on the subject of discontinued treatment and patient adherence, it is conflicting and inconclusive. To date, there are no recognized or universally adopted indices to grade a patient's suitability for routine orthodontic treatment definitively. Orthodontists have been shown to have a subjective or notional opinion on what determines patients' potential for adherence,24 likely to be based on their clinical experience and a knowledge of potentially associated factors.
Patient adherence to treatment is a complex subject, and the evidence supporting various factors that may be implicated is equivocal. In the absence of an index or objective protocol for determining patient adherence to treatment, it would seem sensible to explore factors that may be relevant within a clinician's own practice environment. The second part of this series will describe a study that attempts to identify patient and treatment-related factors associated with discontinued and abandoned treatment in a specialist orthodontic practice.
