To the Editor: There are several limitations
in the data of Dr Aiken and colleagues.1 First,
while the response rate of 52% may compare favorably with rates seen in other
voluntary surveys of health professionals, and the "sample of nurses also
closely resembles those participating in the National Sample Survey of Registered
Nurses," the sample may be less representative of nurses working in hospitals.
Nurses who work in hospitals differ from nurses who work in other settings.2 Second, the number of responses from some hospitals
is low. While for 80% of the hospitals 20 or more nurses provided responses,
there were 50 responses from fewer than half the hospitals. This could introduce
response bias. Third, the failure to weight nurses' responses by the type
of unit or shift on which they work can introduce measurement errors in the
average patient-to-nurse ratio used as the independent variable. A hospital
with a larger proportion of nurses responding who work in intensive care settings
will have a higher patient-to-nurse ratio than a hospital where more medical-surgical
unit nurses respond even if the unit-by-unit staffing ratios are identical.
Kovner C, Needleman J. Nursing Burnout and Patient SafetyNursing Burnout and Patient Safety. JAMA. 2003;289(5):549. doi:10.1001/jama.289.5.549-a