Understanding the Influences Understanding the Influences on the Association between on the Association between

Nurse Staffing and Nurse Staffing and Preventable Patient Preventable Patient

ComplicationsComplications

Deborah Dang, PhD, RNDeborah Dang, PhD, RN2007 Interdisciplinary Research Interest Group2007 Interdisciplinary Research Interest Group

on Nursing Issueson Nursing IssuesAcademy HealthAcademy Health

June 2, 2007June 2, 2007

Problem and SignificanceProblem and SignificanceNurse staffing may be necessary, but Nurse staffing may be necessary, but not sufficient, to prevent adverse not sufficient, to prevent adverse patient eventspatient events

Few studies have examined Few studies have examined characteristics of the work characteristics of the work environment at the unit level that environment at the unit level that may affect staffing may affect staffing

Nurse staffing and characteristics of Nurse staffing and characteristics of the work environment are modifiable the work environment are modifiable features in hospitalsfeatures in hospitals

PurposePurpose

Examine the impact of nurse staffing Examine the impact of nurse staffing and and

potential confounders on preventable potential confounders on preventable

adverse events at the unit level over adverse events at the unit level over a a

seven year period.seven year period.

Research QuestionsResearch Questions

1.1. Is unit-level nurse staffing associated with Is unit-level nurse staffing associated with the failure to rescue, falls, and the failure to rescue, falls, and medication errors between 1998 and medication errors between 1998 and 2004?2004?

2.2. Do unit characteristics confound the Do unit characteristics confound the relationship between nurse staffing and relationship between nurse staffing and adverse events between 1998 and 2004?adverse events between 1998 and 2004?

Central line-associated BSIsCentral line-associated BSIs ++++

Decubitus ulcerDecubitus ulcer ++

FallsFalls ++

Failure to rescueFailure to rescue ++++

Medication errorsMedication errors ++

MortalityMortality ++

Pneumonia, hospital acquiredPneumonia, hospital acquired ++

Pneumonia, vent-associatedPneumonia, vent-associated ++

Post-op PE/DVTPost-op PE/DVT ++

Post-op respiratory failurePost-op respiratory failure ++

UTI, catheter-associatedUTI, catheter-associated ++++

Staffing and Staffing and Strength Strength of of Patient Outcomes Patient Outcomes EvidenceEvidence

++ consistent evidence; + mixed evidence

Conceptual ModelConceptual Model

System

OutcomeIntervention

Client

Quality Health Outcomes Model(Mitchell, Freketich, & Jennings, 1998)

Study ModelStudy Model

System Unit

Nurse Staffing Characteristics•Total hours Agency proportion• RN hours Orientee proportion• RN Proportion RN education• RN shortfall RN experience

RN turnover Patient turnover

OutcomesAdverse Events• Failure to rescue• Falls• Medication errors

Research DesignResearch DesignDesignDesignDescriptive correlational using secondary dataDescriptive correlational using secondary data

SettingSetting945 bed, Magnet-designated, not-for-profit, urban 945 bed, Magnet-designated, not-for-profit, urban

academic medical centeracademic medical center

SampleSampleConvenience sample of 31 adult and pediatric Convenience sample of 31 adult and pediatric

inpatient unitsinpatient units

Unit of analysisUnit of analysisCare-giving unitCare-giving unit

Type of Patients and Level of Type of Patients and Level of CareCare

Adult units: 25 (84%)Adult units: 25 (84%)

Acute care: 16 (52%)Acute care: 16 (52%)

IMC: 8 (26%)IMC: 8 (26%)

ICU: 7 (23%)ICU: 7 (23%)

* > 100% due to rounding* > 100% due to rounding

File DevelopmentFile Development

Design and construct the database and Design and construct the database and merge proceduresmerge procedures

Restructure databaseRestructure database

Develop procedures for handling:Develop procedures for handling: Changes in cost centersChanges in cost centersInconsistent reporting periodsInconsistent reporting periodsHandling missing dataHandling missing data

Construct 3 separate files for analyses:Construct 3 separate files for analyses:Failure to rescue (N = 28)Failure to rescue (N = 28)Falls (n=560)Falls (n=560)Medication errors (n = 341)Medication errors (n = 341)

AnalysesAnalyses

Hospital-level: Failure to RescueHospital-level: Failure to Rescue– DescriptiveDescriptive– Bivariate: zero-order and first-order Bivariate: zero-order and first-order

correlationscorrelations

Unit-level: Falls and Medication errorsUnit-level: Falls and Medication errors– Poisson regression with a robust variance Poisson regression with a robust variance

estimatorestimator– Adjust for type of unitAdjust for type of unit– Account for change in AE rates over time by Account for change in AE rates over time by

including a quadratic function of timeincluding a quadratic function of time

Sample BenchmarksSample Benchmarks

Total HPPDTotal HPPD RN Proportion RN Proportion (%)(%)

AcutAcutee

IMCIMC ICUICU AcutAcutee

IMCIMC ICUICU

Current Current studystudy(31 units)(31 units)

8.78.7 12.712.7 21.521.5 81.581.5 83.783.7 87.587.5

Dunton Dunton (1751 (1751 units)units)

7.6*7.6* 9.1*9.1* 15.9*15.9* 63.663.6 69.769.7 89.289.2

BlegenBlegen(39 units)(39 units)

8.68.6 18.018.0 69.069.0 90.090.0*Median

Unit CharacteristicsUnit Characteristics Overall Overall MeanMean

Agency proportion, %Agency proportion, % 10.0610.06

Orientation proportion, %Orientation proportion, % 5.045.04

RN education, % BSNRN education, % BSN 77.6677.66

RN experience, yearsRN experience, years 7.777.77

RN turnover, %RN turnover, % 9.329.32

Patient turnover, ADT*Patient turnover, ADT* 9.129.12

*admissions, discharges, transfers

Rate of Failure to RescueRate of Failure to Rescue

Correlation: FTR and Correlation: FTR and StaffingStaffing

Zero-order CorrelationZero-order Correlation RR22

Total hoursTotal hours -.795**-.795** .63.63

RN hoursRN hours -.797**-.797** .64.64

RN proportionRN proportion -.085 -.085 .01.01

RN shortfallRN shortfall .678**.678** .46.46

*p < .05, **p < .01

First-order CorrelationFirst-order Correlation

FTR and StaffingFTR and Staffing

Removing:Removing:

Zero-Zero-orderorder

CorrelatioCorrelationn

Agency Agency ProportionProportion

RN RN TurnoverTurnover

Total hoursTotal hours(R(R22))

-.795**-.795**(.63)(.63)

-.756**-.756**(.57)(.57)

-.762**-.762**(.58)(.58)

RN hoursRN hours(R(R22))

-.797**-.797**(.64)(.64)

-.757**-.757**(.57)(.57)

-.767**-.767**(.59)(.59)

RN shortfallRN shortfall(R(R22))

.678**.678**(.46)(.46)

-.679**-.679**(.46)(.46)

.654**.654**(.43)(.43)

Rate of Falls by Type of UnitRate of Falls by Type of Unit (n = 560)(n = 560)

Relative Rate of Falls for each 10% Relative Rate of Falls for each 10% Increase in StaffingIncrease in Staffing

Unadjusted and Adjusted Relative Rates

Rate of Medication Errors by Type of UnitRate of Medication Errors by Type of Unit (n (n = 341)= 341)

Relative Rate of Medication Errors for each Relative Rate of Medication Errors for each 10% increase in Staffing10% increase in Staffing

Unadjusted and Adjusted Relative Rates

Summary of FindingsSummary of Findings

Staffing effect found for all AEsStaffing effect found for all AEs

RN shortfall effect found for FTR and fallsRN shortfall effect found for FTR and falls

Unit characteristics had little to no Unit characteristics had little to no influence on association between staffing influence on association between staffing and AEsand AEs

Unclear explanation for findings in Unclear explanation for findings in unexpected directionunexpected direction

LimitationsLimitations

Measurement errorMeasurement error

Risk adjustment for falls and Risk adjustment for falls and medication errorsmedication errors

Other unmeasured factorsOther unmeasured factors

GeneralizabilityGeneralizability

Implications for PracticeImplications for Practice

Longitudinal data presented Longitudinal data presented opportunity to explore multiple opportunity to explore multiple predictors at the unit levelpredictors at the unit level

Investment needed by hospitals to Investment needed by hospitals to collect and monitor unit-level datacollect and monitor unit-level data

Unique conceptualization and Unique conceptualization and measurement of staffingmeasurement of staffing

Future ResearchFuture Research

Unit-level risk adjustments methodsUnit-level risk adjustments methods

Large scale unit-level studiesLarge scale unit-level studies

Attribution of failure to rescue to Attribution of failure to rescue to unit-levelunit-level

Impact of organizational factors on Impact of organizational factors on staffing and patient outcomesstaffing and patient outcomes

QuestionsQuestions