A questionnaire to assess the generic and disease-specific health outcomes of patients with chronic hepatitis C.
Bayliss MS. Gandek B. Bungay KM. Sugano D. Hsu MA. Ware JE Jr.
Health Institute, New England Medical Center, Boston, MA 02111, USA. firstname.lastname@example.org
A 69-item questionnaire measuring generic functioning and well-being and disease-specific health outcomes was developed and tested using the pre-treatment data from patients with chronic hepatitis C (CHC) participating in two randomized trials of interferon alpha-2b (n = 157). The questionnaire included all eight scales from the SF-36 and measures of nine other generic and disease-specific health concepts. Psychometric tests confirmed the assumptions underlying the construction and scoring of all generic and disease-specific scales. Cross-sectional tests of 'known groups' validity showed that CHC patients scored worse on the generic scales than patients with other chronic conditions and worse than a healthy general population. The generic and disease-specific scale scores were lower in the presence of physical findings of CHC, as hypothesized, but only the physical functioning and bodily pain scales were linked to cirrhosis or extreme alanine aminotransferase (ALT) ratios. This instrument will be useful in studies of health outcome among patients with CHC, a condition whose health burden appears to have been underestimated in studies to date.
Reliability and validity of the Gastrointestinal Symptom Rating Scale in patients with gastroesophageal reflux disease.
Revicki DA. Wood M. Wiklund I. Crawley J.
MEDTAP International, Inc, Bethesda, MD 20814, USA.
The objective of this study was to evaluate the reliability and validity of the gastrointestinal Symptom Rating Scale (GSRS) in US patients with gastroesophageal reflux disease (GERD). Five hundred and sixteen adults with predominant heartburn symptoms of GERD were recruited from gastroenterologist and family physician practices and treated with 6 weeks of 150 mg ranitidine twice daily to identify poorly responsive symptomatic GERD. The GSRS, the Medical Outcomes Study Short Form-36 (SF-36) Health Survey and the Psychological General Well-being (PGWB) scale were administered at baseline and after 6 weeks of treatment. Reported ratings of GERD-related symptoms from physician and patient diaries were measured. The GSRS contains five scales: reflux syndrome, abdominal pain, constipation syndrome, diarrhoea syndrome and indigestion syndrome. The internal consistency reliabilities for the GSRS scales ranged from 0.61 to 0.83 and the intraclass correlation coefficients ranged from 0.42 to 0.60. The GSRS scale scores were correlated with the SF-36 and PGWB scales and with the number and severity of heartburn symptoms. Patients with two or three clinician-rated GERD-related symptoms reported worse GSRS scale scores compared with patients with fewer symptoms (p < 0.0001). Statistically significant differences in the mean GSRS scale scores were observed between treatment responders and non-responders (p < 0.0001) and patients showing a response to treatment had larger mean changes in their GSRS scales than patients not showing a response to treatment (p < 0.0001). The standardized response means ranged from 0.42 to 1.43 for the GSRS scale scores. It was concluded that the GSRS is a brief, fairly comprehensive assessment of common gastrointestinal symptoms. The GSRS has good reliability and construct validity and the GSRS scales discriminate by GERD symptom severity and are responsive to treatment. The GSRS is a useful patient-rated symptom scale for evaluating the outcomes of treatment for GERD.
Disease-specific quality of life: is it one construct?
de Boer AG. Spruijt RJ. Sprangers MA. de Haes JC.
Department of Medical Psychology, Academic Medical Center, University of Amsterdam, The Netherlands. A.G.email@example.com
The objective of this study was to examine the structure of disease-specific quality of life (QoL). Models of QoL with either one overall construct or more constructs were tested and the relationships (factor loadings) between the constructs and dimensions were established, using structural equation modelling. The models were tested over time to assess the stability of the structure. To generalize the results further, disease-specific questionnaires of two very different chronic diseases have been compared: inflammatory bowel disease (IBD) and Parkinson's disease (PD). Questionnaires were mailed in 1994 and a repeated measurement was conducted in 1995. Data were obtained from 222 IBD patients and 235 PD patients. The results show that for both diseases, disease-specific QoL can be considered as one construct. The stability over time of the structure of the QoL models was satisfactory. In PD the factor loadings between the dimensions and QoL were within a small range and remained the same over time, while in IBD, the factor loadings had a larger range and fluctuated more. These results imply that one meaningful sum score can be obtained from these questionnaires.
Use of the Short Form-36 to detect the influence of upper gastrointestinal disease on self-reported health status.
Mant JW. Jenkinson C. Murphy MF. Clipsham K. Marshall P. Vessey MP.
Division of Public Health and Primary Health Care, University of Oxford, UK. firstname.lastname@example.org
Patient-centred outcome measures such as the Short Form-36 (SF-36) have been developed to assess the impact of ill health and medical interventions on self-reported health status. The objective of the study was to assess the impact of gastrointestinal disease upon health status as measured by the SF-36 physical and mental health component scores (PCS and MCS) and to assess whether these component scores might be an appropriate outcome measure for use in clinical research in gastroenterology. The subjects were 364 patients aged between 18 and 64 years who had been prescribed proton pump inhibitors (PPIs) by general practitioners in Oxfordshire. The general practices participating identified patients who had been prescribed PPIs. The data were abstracted from the general practice medical records of these patients concerning gastrointestinal diagnoses and other prescribed medications. The patients were sent the SF-36 questionnaire by post and the PCS and MCS scores were derived, which were adjusted for age and sex and compared with the scores of the general population of the Oxford region. Co-morbidity was assessed by the extent to which non-gastric medications were also used. The commonest diagnoses were oesophagitis/gastro-oesophageal reflux and indigestion. People with these diagnoses had significantly lower health status than the general population. Differences persisted when the results were controlled for the possible effects of co-morbidity. It was concluded that the SF-36 is sensitive to the impact of gastrointestinal disease on health status.
Effects of altering the time of administration and the time frame of quality of life assessments in clinical trials: an example using the EORTC QLQ-C30 in a large anti-emetic trial.
Pater J. Osoba D. Zee B. Lofters W. Gore M. Dempsey E. Palmer M. Chin C.
NCIC Clinical Trials Group, Queen's University, Kingston, Ontario, Canada.
Previous studies conducted by our group suggested that the ability to demonstrate an impact of emesis control on quality of life might depend upon when an quality of life instrument was administered in relation to chemotherapy and on the time frame of the questionnaire. This study was conducted to address this issue. Six hundred and fifty patients receiving moderately emetogenic chemotherapy in a randomized trial comparing a variety of anti-emetic regimens were allocated to four different modes of administration (days 4 and 8; 3 and 7 day time frames) of the QLQ-C30. Patients who completed the questionnaire at the time of maximal impact of chemotherapy (day 3) were more likely to report deterioration in quality of life. Patients who completed questionnaires at day 8 were more likely to report deterioration in quality of life if their questionnaire had a 7 day time frame rather than a 3 day time frame. Patients receiving more effective anti-emetic therapy had better quality of life. It was concluded that better anti-emetic control improves quality of life after moderately emetogenic chemotherapy. In studying quality of life in situations where the impact of treatment waxes and wanes, careful attention needs to be paid to scheduling the administration of questionnaires and to their time frame.