The natural history of prostatism: the effects of non-response bias.
BACKGROUND
In epidemiological studies, non-response may raise the question of generalizability to the target population. Most investigations have not been able to access data that could provide information about the potential impact of non-response bias.


METHODS
A 55% response rate was realized at baseline for a prospective cohort investigation of the natural history of benign prostatic hyperplasia in Olmsted County, Minnesota, during 1989-1991 (the Olmsted County Study of Urinary Symptoms and Health Status Among Men). This prompted a preliminary study of potential non-response bias among full participants, partial participants and complete non-responders. The medical diagnostic index maintained by the Rochester Epidemiology Project was used to ascertain the prevalence of specific conditions in the 9 years prior to study inception.


RESULTS
The age-adjusted period prevalence rate for benign prostatic hyperplasia (%) was 9.6 (95% confidence interval [CI]: 8.1-11.0) for full participants, 8.2 (95% CI: 5.8-10.6) for partial participants and 5.3 (95% CI: 3.6-6.9) for complete non-responders. Other urologic diagnoses followed the same pattern. However, age-adjusted prevalence rates for general medical examination history and major non-urologic morbidities were decidedly similar across response groups.


CONCLUSIONS
These data suggest response may have been driven, in part, by concerns about urologic disease. However, the similarity in non-urologic diagnoses and general medical examinations provide some preliminary reassurance that the 55% response rate did not necessarily compromise generalizability.
Panser
L A
LA
Department of Health Sciences Research, Mayo Clinic, Rochester, MN 55905, USA.
Chute
C G
CG
Guess
H A
HA
Larsonkeller
J J
JJ
Girman
C J
CJ
Oesterling
J E
JE
Lieber
M M
MM
Jacobsen
S J
SJ
D000328:Adult; D000368:Aged; D015982:Bias; D015331:Cohort Studies; D004812:Epidemiologic Methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D011470:Prostatic Hyperplasia / Q000453:epidemiology* / Q000209:etiology*; D014555:Urination Disorders / Q000453:epidemiology* / Q000209:etiology