Validation of a short form Wisconsin Upper Respiratory Symptom Survey (WURSS-21).
BACKGROUND
The Wisconsin Upper Respiratory Symptom Survey (WURSS) is an illness-specific health-related quality-of-life questionnaire outcomes instrument.


OBJECTIVE
Research questions were: 1) How well does the WURSS-21 assess the symptoms and functional impairments associated with common cold? 2) How well can this instrument measure change over time (responsiveness)? 3) What is the minimal important difference (MID) that can be detected by the WURSS-21? 4) What are the descriptive statistics for area under the time severity curve (AUC)? 5) What sample sizes would trials require to detect MID or AUC criteria? 6) What does factor analysis tell us about the underlying dimensional structure of the common cold? 7) How reliable are items, domains, and summary scores represented in WURSS? 8) For each of these considerations, how well does the WURSS-21 compare to the WURSS-44, Jackson, and SF-8?


METHODS
People with Jackson-defined colds were recruited from the community in and around Madison, Wisconsin. Participants were enrolled within 48 hours of first cold symptom and monitored for up to 14 days of illness. Half the sample filled out the WURSS-21 in the morning and the WURSS-44 in the evening, with the other half reversing the daily order. External comparators were the SF-8, a 24-hour recall general health measure yielding separate physical and mental health scores, and the eight-item Jackson cold index, which assesses symptoms, but not functional impairment or quality of life.


RESULTS
In all, 230 participants were monitored for 2,457 person-days. Participants were aged 14 to 83 years (mean 34.1, SD 13.6), majority female (66.5%), mostly white (86.0%), and represented substantive education and income diversity. WURSS-21 items demonstrated similar performance when embedded within the WURSS-44 or in the stand-alone WURSS-21. Minimal important difference (MID) and Guyatt's responsiveness index were 10.3, 0.71 for the WURSS-21 and 18.5, 0.75 for the WURSS-44. Factorial analysis suggested an eight dimension structure for the WURSS-44 and a three dimension structure for the WURSS-21, with composite reliability coefficients ranging from 0.87 to 0.97, and Cronbach's alpha ranging from 0.76 to 0.96. Both WURSS versions correlated significantly with the Jackson scale (W-21 R=0.85; W-44 R=0.88), with the SF-8 physical health (W-21 R=-0.79; W-44 R=-0.80) and SF-8 mental health (W-21 R=-0.55; W-44 R=-0.60).


CONCLUSIONS
The WURSS-44 and WURSS-21 perform well as illness-specific quality-of-life evaluative outcome instruments. Construct validity is supported by the data presented here. While the WURSS-44 covers more symptoms, the WURSS-21 exhibits similar performance in terms of reliability, responsiveness, importance-to-patients, and convergence with other measures.
Barrett
Bruce
B
Department of Family Medicine, School of Nursing, University of Wisconsin-Madison 1100 Delaplaine Ct,, Madison, WI 53715 USA. bruce.barrett@fammed.wisc.edu
Brown
Roger L
RL
Mundt
Marlon P
MP
Thomas
Gay R
GR
Barlow
Shari K
SK
Highstrom
Alex D
AD
Bahrainian
Mozhdeh
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003139:Common Cold / Q000150:complications*; D005260:Female; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014922:Wisconsin; D055815:Young Adult
J Clin Epidemiol. 1992 Dec;45(12):1341-5
1460470
Pediatr Ann. 2005 Jan;34(1):53-7
15693216
Clin Infect Dis. 1999 Feb;28(2):192-4
10064224
Qual Life Res. 2008 Feb;17(1):75-85
18027107
Eur Respir J. 2006 Aug;28(2):358-63
16641127
WMJ. 2007 Dec;106(8):473-80
18237071
Qual Life Res. 1995 Feb;4(1):41-5
7711690
Am J Respir Crit Care Med. 2000 Dec;162(6):2226-31
11112143
Clin Exp Allergy. 1995 Feb;25(2):166-72
7750009
Am J Med. 2002 Apr 22;112 Suppl 6A:33S-41S
11955458
Am J Rhinol. 2000 Sep-Oct;14(5):335-8
11068659
Ann Allergy Asthma Immunol. 1997 Jun;78(6):531-9; quiz 539-40
9207716
JAMA. 1974 Jan 14;227(2):164-9
4357298
J Chronic Dis. 1987;40(2):171-8
3818871
Am J Med. 2002 Apr 22;112 Suppl 6A:4S-12S
11955454
J Infect Dis. 1995 Mar;171(3):584-92
7876605
Control Clin Trials. 1989 Dec;10(4):407-15
2691207
Ann Intern Med. 1960 Oct;53:719-38
13718486
AMA Arch Intern Med. 1958 Feb;101(2):267-78
13497324
J Clin Epidemiol. 1989;42(5):403-8
2659745
Antiviral Res. 2001 Jan;49(1):1-14
11166856
Med Decis Making. 2005 May-Jun;25(3):250-61
15951453
N Engl J Med. 2004 Jan 29;350(5):443-50
14749452
Lancet Infect Dis. 2005 Nov;5(11):718-25
16253889
J Clin Epidemiol. 1996 Nov;49(11):1215-9
8892486
Arch Intern Med. 2003 Feb 24;163(4):487-94
12588210
J Chronic Dis. 1985;38(1):27-36
3972947
J Clin Epidemiol. 2000 Aug;53(8):793-9
10942861
Am J Respir Crit Care Med. 2004 Jul 15;170(2):175-80
15087299
Rhinology. 1985 Dec;23(4):265-71
3001912
Am J Med. 1995 Dec 29;99(6B):24S-27S
8585553
Explore (NY). 2007 Nov-Dec;3(6):561-72
18005908
Antiviral Res. 1996 Mar;29(2-3):287-95
8739607
Ann Fam Med. 2007 May-Jun;5(3):216-23
17548849
Stat Methods Med Res. 2006 Jun;15(3):213-34
16768297
Psychosom Med. 1999 Mar-Apr;61(2):175-80
10204970
Mayo Clin Proc. 2002 Apr;77(4):371-83
11936935
J Chronic Dis. 1987;40(6):473-80
3298292
Am J Public Health Nations Health. 1962 Jun;52:940-5
14450587
J Nerv Ment Dis. 1972 Feb;154(2):79-87
5009724
JAMA. 1967 Nov 6;202(6):494-500
4293015
J Fam Pract. 2002 Mar;51(3):265
11978238
J Clin Epidemiol. 2005 Jun;58(6):609-17
15878475
BMJ. 2002 Mar 9;324(7337):606-7
11884331
Med Decis Making. 2005 Jan-Feb;25(1):47-55
15673581