Health status and health-related quality of life in adolescent survivors of cancer in childhood

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1 Journal of Adolescent Health 38 (2006) Original article Health status and health-related quality of life in adolescent survivors of cancer in childhood Judith Grant, B.Sc., M.B., Ch.B. a, Amy Cranston, B.A. b, John Horsman, B.A. c,d, William Furlong, M.Sc. c,d, Neil Barr, B.Sc. b, Sheri Findlay, M.D. b,e, and Ronald Barr M.B., Ch.B., M.D. b,e, * a Faculty of Medicine, University of Aberdeen, Aberdeen, Scotland b McMaster Children s Hospital, Hamilton, Ontario, Canada c Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada d Health Utilities Inc., Dundas, Ontario, Canada e Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada Manuscript received May 5, 2005; manuscript accepted August 2, Abstract: Keywords: Purpose: Adolescent survivors of cancer in childhood face particular challenges due to their maturational trajectory, including psychosocial adjustments, self-help skills, intellectual functioning and socialization. To better understand these, we assessed the health status and health-related quality of life (HRQL) in a 20-year cohort of such survivors in a single institution. Methods: Health status and HRQL were measured with a self-complete questionnaire from the Health Utilities Index (HUI) family of multi-attribute, preference-based instruments that provide utility scores for single attributes and overall HRQL. Results: Eighty-four (42 males, 42 females) of 129 eligible subjects (65%) participated. More than 80% of the respondents reported some form of morbidity. Overall HRQL utility scores were lower for both the males and females than for corresponding members of the Canadian general population. Female survivors self-reported a significantly greater burden of morbidity (mean overall HUI2/ HUI3 scores:.83/.73 vs..90/.84 for males, p.02), which was most evident in the attributes of emotion and cognition. Conclusions: The majority of adolescent survivors of cancer in childhood carry a morbidity burden into their teen and young adult years. These findings may guide the support required by this population Society for Adolescent Medicine. All rights reserved. Quality of life; Adolescent; Cancer; Health status With the ever-increasing survival rates for children with cancer, it is essential that we focus more attention not only on cure but on helping cancer survivors achieve a future that is as normal as possible [1]. For children who survive cancer, the next phase of their life is adolescence a time of transition during which the teen is expected to undergo various changes that prepare him or her for adult life. The *Address correspondence to: Dr. Ronald Barr, Health Sciences Centre, Room 3N27, McMaster University, 1200 Main Street West, Hamilton, ON L8S 4J9 Canada. address: rbarr@mcmaster.ca process of developmental change is achieved slowly through physical growth, cognitive and neurological development, and extensive learning. It culminates in the young person being physically, socially and emotionally mature. The majority of teens transit through the adolescent years smoothly and uneventfully, but the potential for problems seems obvious when the assault of a potentially fatal malignant disease is superimposed. Some recent reviews have addressed the particular challenges faced by adolescent survivors of cancer [2 4]. These reflect the imposition of the cancer experience on an already challenging maturational trajectory [3]. It has been identified that the cancer experi X/06/$ see front matter 2006 Society for Adolescent Medicine. All rights reserved. doi: /j.jadohealth

2 J. Grant et al. / Journal of Adolescent Health 38 (2006) ence in the adolescent often leads to loss of self-esteem, control and independence, which are all emerging traits in this age group [5]. The population of adolescent cancer survivors has been found to exhibit problems in psychosocial adjustment, selfhelp skills, intellectual functioning and socialization [6]. Observations like these have prompted examination of social support systems for these individuals, with special attention having been paid to the role of the family. It has been shown that adolescent survivors of cancer report lower levels of family cohesion than in a comparative sample of healthy adolescents and their families [2]. Facing such problems, it is not surprising that adolescent survivors of cancer have been reported to exhibit an unusually high prevalence of post-traumatic stress disorder [7]. Ideally, by providing anticipatory guidance and early intervention, some long-term morbidity in adolescent survivors of cancer can be avoided. However, provision of the necessary help requires a better understanding of the issues faced by this population. The objective of this study was to assess the specific and overall burdens of morbidity in adolescent survivors of cancer in childhood using the Health Utilities Index (HUI). The HUI is a family of generic multi-attribute systems for measuring health status and health-related quality of life (HRQL). HUI systems are generic in terms of being applicable to all people aged 5 years and older, and having HRQL utility scales defined such that dead (no health status).00 and full health The systems are reliable and valid, used worldwide, and the most comprehensive available [8]. Standard HUI questionnaires, designed for self-completion by people aged 12 years and older, measure a rich variety of health status attributes (domains or dimensions) and morbidity scores are calculated using wellestablished utility functions [9]. It is hoped that the information gained from this investigation will facilitate the development of an agenda in health education to be promoted with these young people in the context of long-term follow-up focused on their needs. Materials and methods For this study, adolescence was defined as the age range years. This is justified by two considerations. It is the age range used by the Surveillance, Epidemiology and End Results program of the National Cancer Institute in the United States [10] and it is the youngest quintile for which data on health statistics and HRQL have been obtained from Canadian national surveys of the general population using the instruments employed in this study [8]. The entire population of survivors of cancer in childhood, who were younger than 15 years of age at diagnosis, whose management was undertaken at the McMaster Children s Hospital of the Hamilton Health Sciences Corporation, and who were years of age in April 2002, were considered eligible for the study. All eligible subjects were registered with the Pediatric Oncology Group of Ontario, were diagnosed in or after 1982, and had completed treatment by December 31, 2001; a 20-year cohort. Eligible subjects were identified from the database of the hematology-oncology service in the Children s Hospital. The study registration form documented diagnostic, therapeutic and demographic variables, and included the important item of availability of and recruitment to clinical trials, for this has a major influence on outcome [4]. A standard HUI self-complete questionnaire for selfassessed usual health status (HUI23SU.15Q) was completed by each patient. The questionnaire was designed to collect sufficient information to classify the health status of each patient according to both the HUI Mark 2 (HUI2) and Mark 3 (HUI3) systems. Each HUI system consists of two basic components: a health status classification system and a preference-based valuation system. Both HUI2 and HUI3 have strengths and weaknesses and, therefore, these two systems are considered complementary. Each HUI system provides a descriptive measure of health status for each attribute, an interval-scale utility score of morbidity for each attribute, and an interval-scale utility score of overall HRQL. The health status of each study subject is described according to both health status classification systems (HUI2 and HUI3). Each classification system consists of a set of attributes and each attribute has multiple levels of functional capacity. HUI2 consists of seven attributes, each with three to five levels of functioning: sensation, mobility, self-care, emotion, cognition, pain and fertility. HUI3 consists of eight attributes: vision, hearing, speech, ambulation, dexterity, emotion, cognition and pain. Each HUI3 attribute has five or six levels, ranging from no disability through full disability. The complete HUI2 and HUI3 health status classification systems, including full attribute level descriptions, are presented on the following web site: HUI2 and HUI3 systems are complementary because, across the two systems, attributes of the same name have different underlying constructs. The construct for HUI2 emotion focuses on distress and anxiety whereas HUI3 focuses on happiness vs. depression, HUI2 cognition is about learning whereas HUI3 deals with ability to solve day-to-day problems, and pain is measured in terms of severity in HUI3 but frequency and control in HUI2. For example, HUI3 emotion levels range from Happy and interested in life (level 1: no emotional disability) to So unhappy that life is not worthwhile (level 5: most emotional disability). HUI3 cognition levels range from a description of no disability (level 1: Able to remember most things, think clearly and solve day to day problems ) to full disability (level 6: Unable to remember anything at all, and unable to think or solve day to day problems. Standard HUI questionnaires, such as the one used in the study, do not assess fertility and no extra efforts were made

3 506 J. Grant et al. / Journal of Adolescent Health 38 (2006) Table 1 Age of population, sample and nonrespondents by gender at time of diagnosis and study Time Group Gender n Age (years) Min Max SD Median Mean p Value At diagnosis Population Male Female Sample Male Female NR Male Female At time of study Population Male Female Sample Male Female NR Male Female n number of patients; NR nonrespondents; p p value; SD standard deviation. to collect self-assessed levels of fertility for the patients. Attribute levels for each subject were determined from questionnaire responses using standard coding algorithms [9]. A comprehensive HUI health state is defined as a vector consisting of one level from each of the attributes in the classification system. Utility scores of morbidity (i.e., valuation of single-attribute disability) and utility scores of overall HRQL (i.e., valuation of overall disability for the comprehensive health state of each subject) are determined from published utility functions [11 13]. The HUI utility functions (preference-based mathematical scoring models) were used to determine single-attribute utility scores for morbidity and the HRQL of each patient. Utility, rather than value, is the most appropriate type of preference measure for health studies because it is collected under conditions of uncertainty [14]. The published functions, based on preference measurements from samples of the general population, calculate scores representing mean community utilities. The HUI questionnaire was mailed to eligible families, together with the informed consent document, a letter explaining the study and a prepaid reply envelope. Subjects who did not return completed questionnaires and signed informed consent documents within two weeks were contacted by telephone (on a maximum of two occasions at intervals of one week). Packages returned as undelivered prompted contact with the family physicians of most recent record to obtain updated addresses. Single-attribute utility scores are defined on a scale from.00 (the preference score for the lowest functional level of the attribute) to 1.00 (representing the preference score for the highest level full capacity, no disability). Multiattribute utility functions are used to calculate scores of HRQL for the comprehensive health state of each subject on interval scales in which dead.00. HUI2 utility scores are defined on a scale of.03 (representing the utility score of the state having all attribute levels at the lowest functional level) to 1.00 (the utility score for the state having all attributes at the highest functional level Perfect Health). The HUI3 multi-attribute utility scale of HRQL scores is defined from.36 (representing the utility score of the state having all attribute levels at the lowest functional level) to 1.00 (the utility score for the state having all attributes at the highest functional level Perfect Health). Negative HRQL utility scores are associated with states of health considered worse than being dead [15]. Statistical analyses were completed using SPSS versions and 12.0 for Windows (SPSS Inc., Chicago, Illinois). Categorical variables were summarized by frequency distributions and interval-scale variables by summary statistics. The statistical significance of differences was determined using Student s t-test or chi-squared statistics, as appropriate. Differences in mean single-attribute scores.05, and mean HRQL scores.03, are clinically important [9]. The study was approved by the Research Ethics Board of Hamilton Health Sciences and McMaster University. Results A total of 129 eligible subjects were identified as the study population. Eighty-four (65%) returned completed questionnaires (42 male and 42 female) to form the study sample. There were no significant differences between males and females in mean age at diagnosis and at time of study for the eligible population, the sample and nonrespondents (Table 1). There was no statistically significant difference in mean age between sample and nonrespondent patients at time of diagnosis (p.669) or time of study (p.668). The distributions of categories for diagnostic, treatment and disease status variables by study groups are shown in Table 2. The most frequent diagnosis was leukemia (acute lymphoblastic leukaemia [ALL], n 24; acute myelogenous leukaemia [AML], n 5; chronic myelogenous leukemia [CML], n 1) accounting for approximately one-

4 J. Grant et al. / Journal of Adolescent Health 38 (2006) Table 2 Diagnostic and clinical variables for population, sample and nonrespondents Diagnostic and clinical variable Population n (%) Sample n (%) Nonrespondents n (%) Chi-squared test of sample vs. nonrespondents (p value)* Diagnosis Leukemia (ALL, AML, CML) 43 (33) 30 (36) 13 (29) Hodgkin s disease 10 (8) 7 (8) 3 (7) Burkitt s lymphoma 4 (3) 4 (5) 0 Ependymoma 4 (3) 3 (4) 1 (2) Astrocytoma 22 (17) 14 (17) 8 (18) Medulloblastoma 5 (4) 4 (5) 1 (2).433 Neuroblastoma 5 (4) 5 (6) 0 Wilms tumor 10 (8) 7 (8) 3 (7) Renal carcinoma 1 (1) 0 1 (2) Malignant bone tumors 5 (4) 2 (2) 3 (6) Soft tissue sarcomas 7 (6) 6 (6) 1 (2) Gonadal neoplasms 7 (5) 1 (1) 6 (13) Unspecified malignant neoplasms 6 (5) 1 (1) 5 (11) Treatment Surgery 109 (85) 72 (86) 37 (82).601 Radiotherapy 55 (43) 40 (48) 15 (33).118 Chemotherapy 79 (61) 54 (64) 25 (56).332 Clinical trial open Yes 83 (64) 59 (70) 24 (53).292 No 39 (30) 24 (29) 15 (33) Unknown (don t know) 7 (5) 1 (1) 6 (13) Treated on clinical trial Yes 51 (40) 36 (43) 15 (33).292 No 78 (60) 48 (57) 30 (67) Unknown (don t know) Current disease status 1 st Remission 111 (86) 73 (87) 38 (84) 2 nd Remission 5 (4) 5 (6) Stable 6 (5) 5 (6) 1 (2) Progressive 1 (1) 0 1 (2) Unknown (don t know) 6 (5) 1 (1) 5 (11) Other Note that, for testing, categories within variables were aggregated (e.g., diagnosis was re-coded as Leukemia and Other) and Unknown (Don t Know) categories were ignored to avoid small cell sizes making chi-square invalid. n number of patients; ALL acute lymphoblastic leukemia; AML acute myeloid leukemia; CML chronic myeloid leukemia third of the study population and sample. There were no significant differences in regard to types of treatment, availability of a clinical trial for treatment, or treatment on a clinical trial. Most respondents and nonrespondents were in their first remission at the time of study. Overall, only 16 subjects (19%) reported no morbidity in HUI2 and 12 (14%) reported no morbidity in HUI3. Mean HRQL utility scores were significantly lower for females than males in both HUI2 and HUI3 as shown in Tables 3 and 4, respectively. Females had significantly lower mean utility scores than males for HUI2 cognition and pain, and for HUI3 emotion and cognition. The HRQL scores for adolescent females in the Canadian general population (HUI3 95% confidence interval [CI].91 to.93) [16] were higher than for females in the study (HUI3 95% CI.65 to.81). Similarly for males, the HRQL scores in the general population (HUI3 95% CI.93 to.95) [16] were higher than for males in the study (HUI3 95% CI.79 to.90). All differences in mean single-attribute or HRQL utility scores were small (.3) and not statistically significant (p.6) between the two largest diagnositic groups in the sample: leukemia (ALL, AML and CML) and brain tumor (ependymoma, astrocytoma and medulloblastoma) survivors. The sample consisted of 13 females and 17 males in the leukemia group, and 11 females and 10 males in the brain tumor group. Discussion Adolescents who have experienced cancer have been described as the lost tribe [17]. The added burden of cancer imposes a considerable load on the adolescent who is challenged sufficiently by the task of accomplish-

5 508 J. Grant et al. / Journal of Adolescent Health 38 (2006) Table 3 HUI2 single-attribute and HRQL utility scores for all, female and male patients Utility score All patients Female mean Male mean p Value n Mean SD Min Max Sensation Mobility Self care Emotion Cognition * Pain HRQL * p p value for difference between males and females by t-test; n number of patients; Min minimum; Max maximum. * difference is clinically important in size (.05). ing an adult identity and behavior. As has been observed recently, In such circumstances, it is a small wonder that many adolescents with cancer travel a difficult path in seeking a return to normality, some bearing permanent scars (both physical and emotional) from their journey [18]. But how should this combined burden of morbidity be measured? Instruments designed to assess health status and HRQL provide a solution [19]. Several generic health profile measures have been developed for use in adolescent populations [20 26] and some of these have been employed in the assessment of HRQL in young people with cancer, both during and after therapy [23,24]; attesting to the burden of morbidity borne by adolescents with malignant disease. The approach adopted in the study reported here was to use a preference-based measure of HRQL based on self-assessed health status; an approach, to our knowledge, not taken previously with this group of subjects. Self-assessment was selected for practical reasons and on normative grounds. Self and proxy questionnaire assessments, and questionnaire and physiological assessments are complementary. The evidence about agreement of HUI utility scores from self and proxy questionnaire measurements is mixed, varying by types of assessors and scores. Agreement is typically moderate or better in cases in which proxy assessors have comprehensive knowledge of the subjects (e.g., proxies are parents of subjects) and for readily assessable attributes such as ambulation and dexterity [27,28] Agreement is generally poor for less observable attributes such as emotion, cognition and pain. The advantages of preference-based measures include the ability to integrate morbidity with mortality and the generation of utility scores for use in economic evaluations known as cost-utility analyses [14]. An added advantage of the Health Utilities Index is the availability of normative data for a large, agematched general population [8]. A response rate of 65% to mailed-out questionnaires for adolescent respondents is considerably higher than that reported by others [25] and reflects the importance of the follow-up contact strategy, as has been the experience elsewhere [29,30]. It is of particular note that more than 80% of the respondents reported some form of morbidity. Consistent with our earlier studies of survivors of specific cancers in childhood, the main burdens having mean single-attribute utility scores less than.95 were in the attributes (domains/dimensions) of Table 4 HUI3 single-attribute and HRQL scores for all, female and male patients Utility score All patients Female mean Male mean p Value n Mean SD Min Max Vision Hearing Speech Ambulation Dexterity Emotion * Cognition * Pain HRQL * p p value for differences between males and females by t-test; n number of patients; Min minimum; Max maximum. * difference is clinically important in size (.05).

6 J. Grant et al. / Journal of Adolescent Health 38 (2006) emotion, cognition and pain. Again, as we had observed previously, the overall burden of morbidity is greater in survivors of brain tumors than in survivors of acute lymphoblastic leukemia those previous studies reporting from the perspective of parental proxy assessors [31]. As expected, both male and female survivors reported poorer HRQL than did their counterparts in the general population. However, the female survivors reported more morbidity than did the males in emotion and cognition; a result not explained by the respective disease distributions. This gender distinction in morbidity burden reported by young survivors of cancer in childhood has been observed by others [20,32]. Limitations of this study include the lack of information on socioeconomic status, ethnicity, educational attainment and employment experience. Although the results reflect the outcomes in a 20-year cohort, these were obtained in a single institution. It is to be hoped that other investigators will add their material to this important area of study. The information obtained in this study adds to the available literature indicating that the majority of adolescent survivors of cancer in childhood carry the burden of their illness and treatment experience into their teen and young adult years. This underscores the need to continue to anticipate these difficulties and develop strategies to support young people who are most likely to be affected. Further studies should focus on the numerous variables, especially with respect to treatment modalities, that influence the morbidity burden. Information such as that provided by this study should contribute to the development of programs in health promotion and education for childhood cancer survivors as they are encouraged to participate in long-term follow-up; an initiative yet in its infancy [33]. Acknowledgments Judith Grant received support from Cancer Research UK, the Enid Linder Foundation, the British Medical and Dental Students Trust, and the Health Utilities Inc. Student Grant program to enable her to undertake this study. We thank Danielle Hunter and Danielle Talsma for data analysis. The results were presented in part at the annual meeting of the International Society of Pediatric Oncology (SIOP) in Cairo, Egypt in October, References [1] Barr RD, Sala A. Quality-adjusted survival: a rigorous assessment of cure after cancer during childhood and adolescence. Pediatr Blood Cancer 2005;44: [2] Barr RD. On cancer control and the adolescent. Med Pediatr Oncol 1999;32: [3] Whyte F, Smith L. 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