Gastrointestinal (GI)-Specific patient reported outcomes instruments differentiate between renal transplant patients with or without GI symptoms: results from a South American cohort

Gerardo Machnicki, Jacqueline Pefaur, Luis Gaite, Ana M Linchenco, Clemente Raimondi, Ruben Schiavelli, Alcira Otero, Mary Kay Margolis, Gerardo Machnicki, Jacqueline Pefaur, Luis Gaite, Ana M Linchenco, Clemente Raimondi, Ruben Schiavelli, Alcira Otero, Mary Kay Margolis

Abstract

Background: Immunosuppressive therapies have burdensome side effects which may lead to sub-therapeutic dosing and non-compliance. Patients on different immunosuppressant regimens may feel less bothered by Gastrointestinal (GI) side effects or report better health-related quality of life (HRQL). We evaluated the reliability and validity of two GI-specific outcome instruments (Gastrointestinal Symptom Rating Scale (GSRS; higher scores = increased severity) and Gastrointestinal Quality of Life Index (GIQLI; higher scores = better GI-specific HRQL)) in renal transplant patients in South America.

Methods: Data from 5 South American centers participating in an international, longitudinal, observational study were analyzed. Patients were > or = 1 month post transplant and on mycophenolate mofetil (MMF) and a calcineurin inhibitor. Patients completed the GSRS, GIQLI, and Psychological General Well-Being (PGWB; higher scores = better HRQL) Index at baseline and at 4-6 weeks. Internal consistency, test-retest reliability and construct and discriminant validity were assessed.

Results: Sixty-two participants were enrolled. Mean age was 42 years; mean time since transplant was 3.3 years; 57% were male; 65% received a deceased organ transplant and 68%had GI events. The GSRS and GIQLI demonstrated high internal consistency (Cronbach's alphas 0.72-0.96). Test-retest reliability was adequate (intraclass correlation coefficient > 0.6) for all GIQLI subscales and all GSRS subscales except Diarrhea and Reflux syndrome. Correlations between the GSRS and PGWB were moderate (range: -0.21 to -0.53, all p < 0.001 except 6 correlations with p < 0.05); correlations between the GIQLI and PGWB were higher (range: 0.36 to 0.71 p < 0.001), indicating good construct validity. The GSRS and GIQLI demonstrated good discriminant validity, as they clinically and statistically distinguished between patients with and without GI complaints and among patients with varying GI complication severity. Patients with GI complaints reported higher GSRS scores than patients without complaints (all p < 0.001). GIQLI scores were lower in patients with GI complaints than patients without complaints (all p < 0.001). The GSRS and GIQLI differentiated among patients with four GI severity levels (overall Kruskall-Wallis test p < 0.001, except for one scale). The GSRS and GIQLI are acceptable for use in South American renal transplant patients. These two instruments demonstrate adequate reliability and validity. Patients with GI complaints reported poor HRQL and strategies are needed to improve patients' HRQL.

Figures

Figure 1
Figure 1
GSRS Subscale Scores by Presence/Absence of GI Complaints.
Figure 2
Figure 2
GIQLI Subscale Scores by Presence/Absence of GI complaints ***.

References

    1. Chan L, Mulgaonkar S, Walker R, Arns W, Ambuhl P, Schiavelli R. Patient-reported gastrointestinal symptom burden and health-related quality of life following conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium. Transplantation. 2006;81:1290–1297. doi: 10.1097/01.tp.0000209411.66790.b3.
    1. Kleinman L, Faull R, Walker R, Ramesh Prasad GV, Ambuehl P, Bahner U. Gastrointestinal-specific patient-reported outcome instruments differentiate between renal transplant patients with or without GI complications. Transplant Proc. 2005;37:846–849. doi: 10.1016/j.transproceed.2004.12.106.
    1. Kleinman L, Kilburg A, Machnicki G, Faull R, Walker R, Prasad R, Ambuehl P, Bahner U, Margolis MK. Using GI-specific patient outcome measures in renal transplant patients: validation of the GSRS and the GIQLI. Qual Life Res. 2006;15:1223–132. doi: 10.1007/s11136-006-0053-5.
    1. Dimenas E, Glise H, Hallerback B, Hernqvist H, Svedlund J, Wiklund I. Well-being and gastrointestinal symptoms among patients referred to endoscopy owing to suspected duodenal ulcer. Scand J Gastroenterol. 1995;30:1046–1052. doi: 10.3109/00365529509101605.
    1. Dimenas E, Carlsson G, Glise H, Israelsson B, Wiklund I. Relevance of norm values as part of the documentation of quality of life instruments for use in upper gastrointestinal disease. Scand J Gastroenterol Suppl. 1996;221:8–13. doi: 10.3109/00365529609095544.
    1. Kulich KR, Pique JM, Vegazo O, Jimenez J, Zapardiel J, Carlsson J, Wiklund I. [Psychometric validation of translation to Spanish of the gastrointestinal symptoms rating scale (GSRS) and quality of life in reflux and dyspepsia (QOLRAD) in patients with gastroesophageal reflux disease] Rev Clin Esp. 2005;205:588–594.
    1. Guyatt GH, Osoba D, Wu AW, Wyrwich KW, Norman GR. Methods to explain the clinical significance of health status measures. Mayo Clin Proc. 2002;77:371–383.
    1. Eypasch E, Williams JI, Wood-Dauphinee S, Ure BM, Schmulling C, Neugebauer E, Troidl H. Gastrointestinal Quality of Life Index: development, validation and application of a new instrument. Br J Surg. 1995;82:216–222. doi: 10.1002/bjs.1800820229.
    1. Dupuy H. The Psychological General Well-Being (PGWB) Index. In: Wenger NK, Mattson ME, Furberg CD, Elinson J, editor. Asessment of quality of life in clinical trials of cardiovascular therapies. Washington, DC , Le Jacq Publishing; 1984. pp. 170–183.
    1. Nunnaly JC, Bernstein IH. Psychometric Theory. 3rd. New York , McGraw-Hill, Inc.; 1994.
    1. Hays R, Anderson R, Revicki DA. Assessing reliability and validity of measurement in clinical trials. In: Staquet MJ, Hays RD, Fayers P, editor. Quality of life assessment in clinical trials. New York , Oxford University Press; 1998.
    1. Leidy NK, Revicki DA, Geneste B. Recommendations for evaluating the validity of quality of life claims for labeling and promotion. Value Health. 1999;2:113–127. doi: 10.1046/j.1524-4733.1999.02210.x.
    1. Fayers P, Machin D. Quality of life: Assessment, Interpretation and analysis. New York , John Wiley & Sons, Ltd.; 2000.
    1. Revicki DA, Wood M, Wiklund I, Crawley J. Reliability and validity of the Gastrointestinal Symptom Rating Scale in patients with gastroesophageal reflux disease. Qual Life Res. 1998;7:75–83. doi: 10.1023/A:1008841022998.
    1. Jenney ME, Campbell S. Measuring quality of life. Arch Dis Child. 1997;77:347–350.
    1. Talley NJ, Fullerton S, Junghard O, Wiklund I. Quality of life in patients with endoscopy-negative heartburn: reliability and sensitivity of disease-specific instruments. Am J Gastroenterol. 2001;96:1998–2004. doi: 10.1111/j.1572-0241.2001.03932.x.

Source: PubMed

Sponsoren und Mitarbeiter

Krankheiten

Drogeninterventionen

3
Abonnieren