What do we mean by adulthood?

Research in this area has given most attention to early adulthood, particularly focusing on individuals in their early 20s (at the end of adolescence), while fewer studies have followed up people into their 30s and beyond. This may be attributed to the fact that interest in psychosocial sequelae is relatively recent, reflecting the considerable improvements in survival and physical health consequent on advances in paediatric care over recent years. It is important to ascertain whether the increased survival is associated with a good enough quality of life in psychosocial as well as in physical terms. The implications of illness in these two age groups (20s and early 30s as compared to 30s and beyond) might be expected to be very different. The younger adults are in a state of psychosocial transition, negotiating the move from dependence to independence and being faced with adult decisions about relationships and work. Older adults are likely to have more established patterns of functioning in these areas. In addition, new physical complications may arise with older age and this may also impact on psychosocial functioning. It is therefore difficult to generalise the findings of studies in this area from one age group to another.

What is meant by psychosocial outcome?

This may be divided into psychiatric and social outcome. Psychiatric morbidity indicates the presence of significant psychological symptoms or psychopathology. This is defined as the presence of handicapping abnormalities of emotions, behaviour, and relationships. It means that any psychological symptoms present are so pronounced that they cause handicap or impede personal and social functioning. Another psychological marker used in some studies is self esteem. This is generally thought of as an individual's assessment of their own self worth with regard to attained qualities and performance in relation to those that they desire. This is usually measured by questionnaire. Although lowered self esteem is a key symptom of some psychiatric disorders such as depression, its associations with other disorders are not well established. Its main interest from a psychopathological perspective may lie in the fact that low self esteem may be a vulnerability factor for the later development of psychiatric disorder.8

The measures included in the quantification of social outcome differ between studies. They include educational attainment, occupational status, marital status, social relationships, and place of residence (within or outside the parental home).

How can psychological symptoms best be assessed?

The presence of psychological symptoms can be objectively measured by the use of questionnaires and interviews. The best are those with established psychometric properties showing satisfactory reliability and validity data for the population under study. Questionnaires are a useful means of rapidly obtaining standardised information from small and large samples. However, they are only a measure of “risk for” psychiatric disorder and do not necessarily reflect the true presence or absence of diagnoses or associated functional impairment.

To convincingly assess the presence of significant psychological problems causing impairment, interviews are usually required which enquire in detail about the severity, duration, and handicap caused by any psychological complaints. A number of standardised psychiatric research interviews have been developed. They are more costly and time consuming to administer than questionnaires and require trained research staff to do so. We will indicate when information is derived from questionnaires or from validated research interviews but we regard the latter as providing more robust information about psychopathology.

It is helpful to describe the psychiatric and social adjustment of survivors of chronic illness separately, because although the two may influence each other, they do not always run parallel courses and each are of interest in their own right. However, when assessing social outcome, it is important to differentiate objective from subjective indicators. For example, survivors of illness may be comparable to general population norms on social indicators and yet feel disadvantaged in these areas; the converse may also be true.

An additional consideration when discussing objective social indicators is that there may be geographic and cultural differences of relevance to interpretation of the findings. For example, levels of unemployment and age of marriage may vary in different countries.

Study design

Examining the psychosocial outcome in adulthood for survivors of chronic physical illness would ideally start by assessing psychiatric and social adjustment in children even prior to the inception of their physical illness through birth cohort studies. However, such studies are a large and expensive undertaking and the assessments of psychological and social functioning are by necessity frequently brief and not optimal for quantification of these measures, unless psychosocial outcome is included as a primary objective of the study and appropriate measures incorporated into its design. Large, longitudinal birth cohorts may be useful when studying a mix of the more common and less severe conditions but they are not an efficient way of identifying children with individual severe and rare conditions, who may be expected to be at higher risk for suffering psychosocial sequelae. An additional factor complicating the use of this study design is that physical treatments are continually advancing and by the time the sample reaches adulthood, their developmental experiences may be quite different from those of children currently being diagnosed with the same condition who may have a more optimistic life expectancy and more effective treatment options available.

A more common research strategy is the comparison of adults with a history of childhood chronic illness compared to a control group. Individuals known to tertiary services are frequently identified as the index group. They are likely to represent those more severely affected. Individuals in these studies may be more homogeneous with regard to diagnostic group and the smaller sample size makes the use of interview based measures of psychiatric adjustment more likely.

What about a control group?

In assessing psychosocial outcome, a crucial issue is the choice of control group. Different control groups, for example, general population, siblings will answer different questions. It is important to acknowledge that the experiences of siblings are also likely to have been affected by the illness.

General population or healthy controls are most commonly used as the most important issue is likely to be to what extent psychosocial adjustment differs in adult survivors from that of healthy subjects of comparable age, gender, and social class. Sociodemographic differences between the populations may contribute more to any differences found than the illness experience itself and so it is important to match for as many of these factors as possible.

The comparison of adult outcome between subjects suffering from different diagnoses (without brain involvement) is unlikely to be helpful unless these conditions differ in some specific aspect which is considered likely to lead to different rates of psychopathology.

A different question with regard to psychosocial sequelae is factors within specific conditions which might influence their outcome. These may be biological, for example, severity of illness, persistence of symptoms into adulthood, or psychosocial factors. Assessment of their contribution necessitates within group analyses and this is likely to require large sample sizes.

What do we know of the psychosocial outcome of childhood chronic illness?

Table 1 presents details of some of the studies whose findings will be discussed. This highlights some of the differences in case mix, control groups, size of the study, age at assessment, and the quality of the main outcome measures used.

Studies of heterogeneous diagnostic groups

Studies focusing on a specific disorder

Conclusions

In trying to reach conclusions from the available literature, its inherent methodological difficulties must be taken into consideration; these include heterogeneous samples, variable outcome measures, and differing control groups. However, despite this, there is considerable agreement with regard to many of the findings. This consistency is maintained for studies with both large and small sample sizes, across individuals with different conditions, and in different countries. Furthermore, the results of studies using well validated psychiatric interviews such as the Present State Examination and the Schedule for Affective Disorders and Schizophrenia are similar to those of studies using questionnaire based measures in showing that psychiatric outcome is not severely compromised in the majority of adult survivors (without brain involvement) when compared with healthy or general population controls. Some studies have indicated that persistent physical health problems in adulthood may be related to the presence of greater or more severe psychiatric disorder and others have suggested that psychiatric outcome may be better for men than for women. However, when interpreting these findings, consideration needs to be given to the fact that studies on some specific conditions may be carried out in units which pay special attention to psychosocial aspects of physical disorders. Outcomes may be less optimistic among units or individuals who do not participate in these studies. Adult outcome may also be related to the quality of paediatric care and psychosocial support.

The evidence regarding social outcome—objective indicators of educational attainment, employment, and the development of independence—suggests that there is mild impairment when compared to the general population. Persistent severe illness in adulthood seems to be related to poorer outcome in these domains. However, these findings do not take into consideration more subjective indicators which suggest that the experience of chronic illness may change an individual's views about what is important in life.40 Lesser academic achievement, lower employment, and delayed independence may be achieved by an alteration in an individual's personal life goals and might represent part of an adaptive process. In particular, studies have interpreted the delay in social maturation in this way. Studies which follow up individuals into later adulthood will be important in clarifying this to see whether this group eventually catches up developmentally.

The study of psychosocial outcome in adults with chronic illness since childhood is not easy, both because of the heterogeneity of physical disease severity, the rapid progression of physical treatments, and the many other factors—in the individual, his/her family, and their social environment—which may predispose to psychosocial difficulties. To adequately account for these factors, large study samples are needed. Some of the studies discussed have had small sample sizes and it is possible that this may account for negative results in these cases.

Further research in this area might helpfully focus efforts on the acquisition of larger samples, not just from more specialised units (who may be more sensitive to psychological difficulties), which is reflected in a more optimistic psychosocial prognosis. Despite this possibility the evidence shows similar results in a sample drawn from a Finnish teaching hospital and from a British birth cohort study.9 ,13 While the majority of children with chronic illness are not compromised in adult life with regard to these domains, future research might usefully focus on identifying those most likely to develop difficulties. This might involve further exploration of the role of adjustment disorder and low self esteem in childhood, persistence and severity of physical illness, school attendance, and family factors which may affect adult outcome. This may lead on to the evaluation of interventions aimed at reducing this risk.

There is a need for well designed studies in this field, as life expectancy for these children continues to increase. At present, there is no consistent evidence that psychosocial functioning is severely compromised, but it is likely that chronic physical illness has a differential impact on different individuals. Understanding this more thoroughly is likely to be important, not only in terms of quantifying the impact of chronic illness but also in facilitating the targeting of therapeutic interventions.