Morten Aa. Petersen

LONGITUDINAL STUDY OF SEXUAL FUNCTION AND VAGINAL CHANGES AFTER RADIOTHERAPY FOR CERVICAL CANCER

PURPOSE To investigate the longitudinal course of self-reported sexual function and vaginal changes in patients disease free after radiotherapy (RT) for locally advanced, recurrent, or persistent cervical cancer. MATERIALS AND METHODS A total of 118 patients referred for RT were included. The patients were assessed, using a validated self-assessment questionnaire, at the termination of RT and 1, 3, 6, 12, 18, and 24 months later. The results were compared with an age-matched control group from the general population. RESULTS Persistent sexual dysfunction and adverse vaginal changes were reported throughout the 2 years after RT, with small changes over time: approximately 85% had low or no sexual interest, 35% had moderate to severe lack of lubrication, 55% had mild to severe dyspareunia, and 30% were dissatisfied with their sexual life. A reduced vaginal dimension was reported by 50% of the patients, and 45% were never, or only occasionally, able to complete sexual intercourse. Despite sexual dysfunction and vaginal adverse effects, 63% of those sexually active before having cancer remained sexually active after treatment, although with a considerably decreased frequency. CONCLUSIONS Patients who are disease free after RT for locally advanced, recurrent, or persistent cervical cancer are at high risk of experiencing persistent sexual and vaginal problems compromising their sexual activity and satisfaction.

Early-stage cervical carcinoma, radical hysterectomy, and sexual function. A longitudinal study.

Limited knowledge exists concerning the impact of radical hysterectomy (RH) alone on the sexual function of patients with early‐stage cervical carcinoma. The authors investigated the longitudinal course of self‐reported sexual function after RH.

Self-assessment in Cancer patients referred to palliative care: A study of feasibility and Symptom epidemiology

Research in palliative care is considered difficult due to the poor health of patients. However, patient‐provided data are essential for a thorough description of patient symptomatology and for the evaluation of care.

Use of differential item functioning analysis to assess the equivalence of translations of a questionnaire

In cross-national comparisons based on questionnaires, accurate translations are necessary to obtain valid results. Differential item functioning (DIF) analysis can be used to test whether translations of items in multi-item scales are equivalent to the original. In data from 10,815 respondents representing 10 European languages we tested for DIF in the nine translations of the EORTC QLQ-C30 emotional function scale when compared to the original English version. We tested for DIF using two different methods in parallel, a contingency table method and logistic regression. The DIF results obtained with the two methods were similar. We found indications of DIF in seven of the nine translations. At least two of the DIF findings seem to reflect linguistic problems in the translation. ‘Imperfect’ translations can affect conclusions drawn from cross-national comparisons. Given that translations can never be identical to the original we discuss how findings of DIF can be interpreted and discuss the difference between linguistic DIF and DIF caused by confounding, cross-cultural differences, or DIF in other items in the scale. We conclude that testing for DIF is a useful way to validate questionnaire translations.

Health related quality of life in a nationally representative sample of haematological patients

Objectives:  Knowledge of health related quality of life of haematological patients is limited. This study aimed at investigating the prevalence and predictors of symptoms and problems in a representative sample of haematological patients in Denmark.

Neuropsychological assessment of chronic non-malignant pain patients treated in a multidisciplinary pain centre.

The aim of the study was to investigate the influence of pain, sedation, pain medications and socio‐demographics on cognitive functioning in chronic non‐malignant pain patients. Chronic non‐malignant pain patients (N = 91) treated in a multidisciplinary pain centre were compared with age and sex matched healthy volunteers (N = 64). Furthermore four subgroups of patients were examined: Group 1 (N = 21) received no pain medications, group 2 (N = 19) were in long‐term oral opioid treatment, group 3 (N = 18) were treated with antidepressants and/or anticonvulsants and group 4 (N = 33) were treated with a combination of long‐term oral opioids and antidepressants and/or anticonvulsants. Assessments comprised pain (PVAS) and sedation (SVAS), Continuous Reaction Time (CRT) testing for sustained attention, Finger Tapping Test (FTT) testing for psychomotor speed, Paced Auditory Serial Addition Task (PASAT) testing for information processing and working memory and Mini Mental State Examination (MMSE). CRT and FTT were impaired in the total patient sample. Treatment with opioids was associated with poorer performance of PASAT. High scores of PVAS and SVAS were associated with poor performance of PASAT and CRT, respectively. MMSE seems to be too insensitive for detecting the milder forms of cognitive impairment found in chronic non‐malignant patients.

Symptoms and problems in a nationally representative sample of advanced cancer patients.

Little is known about the need for palliative care among advanced cancer patients who are not in specialist palliative care. The purpose was to identify prevalence and predictors of symptoms and problems in a nationally representative sample of Danish advanced cancer patients. Patients with cancer stage 3 or 4 from 54 hospital departments (n = 1630) received the EORTC QLQ-C30 questionnaire. Mean scores were calculated according to the scoring manual and in addition a ‘symptom/problem’ and a ‘severe symptom/problem’ was defined and calculated. Multiple logistic regression was used to identify predictors. In total, 977 (60%) patients participated. The most frequent symptoms/problems were fatigue (57%; severe 22%) followed by reduced role function, insomnia and pain. Age, cancer stage, primary tumour, type of department, marital status and whether the patient had recently been hospitalized or not were associated with several symptoms and problems. This is probably the first nationally representative study of its kind. It shows that advanced cancer patients in Denmark have symptoms and problems that deserve attention and that some patient groups are especially at risk.

A simulation study provided sample size guidance for differential item functioning (DIF) studies using short scales

OBJECTIVE Differential item functioning (DIF) analyses are increasingly used to evaluate health-related quality of life (HRQoL) instruments, which often include relatively short subscales. Computer simulations were used to explore how various factors including scale length affect analysis of DIF by ordinal logistic regression. STUDY DESIGN AND SETTING Simulated data, representative of HRQoL scales with four-category items, were generated. The power and type I error rates of the DIF method were then investigated when, respectively, DIF was deliberately introduced and when no DIF was added. The sample size, scale length, floor effects (FEs) and significance level were varied. RESULTS When there was no DIF, type I error rates were close to 5%. Detecting moderate uniform DIF in a two-item scale required a sample size of 300 per group for adequate (>80%) power. For longer scales, a sample size of 200 was adequate. Considerably larger sample sizes were required to detect nonuniform DIF, when there were extreme FEs or when a reduced type I error rate was required. CONCLUSION The impact of the number of items in the scale was relatively small. Ordinal logistic regression successfully detects DIF for HRQoL instruments with short scales. Sample size guidelines are provided.

Differential item functioning (DIF) analyses of health-related quality of life instruments using logistic regression

BackgroundDifferential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise when testing for DIF in HRQoL instruments. We focus on logistic regression methods, which are often used because of their efficiency, simplicity and ease of application.MethodsA review of logistic regression DIF analyses in HRQoL was undertaken. Methodological articles from other fields and using other DIF methods were also included if considered relevant.ResultsThere are many competing approaches for the conduct of DIF analyses and many criteria for determining what constitutes significant DIF. DIF in short scales, as commonly found in HRQL instruments, may be more difficult to interpret. Qualitative methods may aid interpretation of such DIF analyses.ConclusionsA number of methodological choices must be made when applying logistic regression for DIF analyses, and many of these affect the results. We provide recommendations based on reviewing the current evidence. Although the focus is on logistic regression, many of our results should be applicable to DIF analyses in general. There is a need for more empirical and theoretical work in this area.

The relationship between overall quality of life and its subdimensions was influenced by culture : analysis of an international database

OBJECTIVE To investigate whether geographic and cultural factors influence the relationship between the global health status quality of life (QL) scale score of the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire and seven other subscales representing fatigue, pain, physical, role, emotional, cognitive, and social functioning. STUDY DESIGN AND SETTING A large international database of QLQ-C30 responses was assembled. A linear regression model was developed predicting the QL scale score and including interactions between geographical/cultural groupings and the seven other scale scores. RESULTS The pain subscale appeared to have relatively greater influence and fatigue relatively lower influence for those from other European regions compared with respondents from the UK when predicting overall quality of life (QoL). For Scandinavia physical functioning appeared to contribute relatively less. There was evidence of greater emphasis on cognitive functioning for those from South Asia and Latin America compared with the UK, whereas for those from Islamic countries, the role functioning scale appeared to have less influence and physical and social functioning more influence. CONCLUSION These results provide evidence that different cultural groups may emphasize different aspects of their QoL. This has implications for studies using QoL questionnaires in international comparisons.