human capital in the nursing workforce and its impact on patient outcomes

Human Capital in the Nursing Human Capital in the Nursing Workforce and Its Impact on Workforce and Its Impact on

Patient OutcomesPatient Outcomes

Ciaran S. Phibbs, Ph.D.Ciaran S. Phibbs, Ph.D.June 2, 2007June 2, 2007

Health Economics Resource CenterHealth Economics Resource Center

Research TeamResearch TeamInvestigatorsInvestigators

Ann BartelAnn BartelPatricia StonePatricia StoneNancy BeaulieuNancy Beaulieu

Programmers and Research AssistantsProgrammers and Research AssistantsLakshmi Ananath Lakshmi Ananath Cecilia MachadoCecilia MachadoSusan SchmittSusan SchmittAndrea ShaneAndrea Shane


BackgroundBackground

Relationship between hospital nurse staffing and Relationship between hospital nurse staffing and quality of care is a significant concern for health quality of care is a significant concern for health services researchers, health services providers services researchers, health services providers and policymakers. and policymakers.

Prior research has found evidence showing Prior research has found evidence showing negative correlation between adverse patient negative correlation between adverse patient outcomes and nurse staffing levels, but this outcomes and nurse staffing levels, but this literature has numerous limitations. literature has numerous limitations.


What Our Paper ContributesWhat Our Paper Contributes

Unit-level dataUnit-level dataMonthly observationsMonthly observationsLongitudinal 4 years. Longitudinal 4 years. Data from a single organization (VA). Data from a single organization (VA). Adds role played by human capital and Adds role played by human capital and

relational capital in the nursing workforcerelational capital in the nursing workforce


Hypotheses We TestHypotheses We Test

RNs with more general human capital RNs with more general human capital (education, experience) deliver higher quality (education, experience) deliver higher quality nursing carenursing care

RNs with more firm-specific human capital (job RNs with more firm-specific human capital (job tenure) deliver higher quality nursing caretenure) deliver higher quality nursing care

Relational capital (stability of nursing team) Relational capital (stability of nursing team) contributes to higher quality care because contributes to higher quality care because stable teams are better at sharing tacit stable teams are better at sharing tacit knowledge and facilitating coordination.knowledge and facilitating coordination.


Nurse Staffing DataNurse Staffing Data

DSS, VA’s implementation of TSI, a DSS, VA’s implementation of TSI, a comprehensive hospital activity based comprehensive hospital activity based accounting system.accounting system.

Inpatient nursing labor tracked at the Inpatient nursing labor tracked at the unit level.unit level.


Nurse Staffing DataNurse Staffing Data Monthly extract that reports the Monthly extract that reports the

number of hours, for each type of number of hours, for each type of nursing labor, including:nursing labor, including:– RNsRNs– LVNsLVNs– AidesAides– Advanced practice nursesAdvanced practice nurses– OthersOthers


Nurse Staffing DataNurse Staffing Data

Hours worked and costs reported Hours worked and costs reported separately for “regular” hours, separately for “regular” hours, overtime, and vacation/sick/holiday overtime, and vacation/sick/holiday hours. Thus, we can track nursing hours. Thus, we can track nursing labor by the actual hours worked, not labor by the actual hours worked, not the hours nurses were paid. the hours nurses were paid.


Human Capital DataHuman Capital Data We extracted human capital and other We extracted human capital and other

nursing characteristics from the VA payroll nursing characteristics from the VA payroll data (PAID). These data contain a wealth data (PAID). These data contain a wealth of information, including VA tenure, of information, including VA tenure, education, and age.education, and age.

PAID also reports hours of overtime and PAID also reports hours of overtime and shift premiums (track off-shift labor).shift premiums (track off-shift labor).


Human Capital DataHuman Capital Data

DSS tracks where people work to DSS tracks where people work to allocate costs. allocate costs.

DSS made a special extract for us that DSS made a special extract for us that summarized, by PAID codes, how all summarized, by PAID codes, how all nursing labor was allocated across nursing labor was allocated across units, for each facility.units, for each facility.


Patient DataPatient Data Unlike most discharge abstracts, VA Unlike most discharge abstracts, VA

has a “bedsection” file, with one record has a “bedsection” file, with one record for each bedsection stay, which are for each bedsection stay, which are defined by the treating specialty of the defined by the treating specialty of the physician. ICUs are separate physician. ICUs are separate bedsections.bedsections.– Thus, most, but not all, unit stays have a Thus, most, but not all, unit stays have a

corresponding bedsection record.corresponding bedsection record.


Empirical ModelEmpirical ModelPSIPSIitit = α = α11(RN Hrs PPD)(RN Hrs PPD)itit + α + α22(RN Hrs PPD(RN Hrs PPD22 ) )it it + +

αα3 3 HCHCitit + α + α44 Non-RN Hours PPD Non-RN Hours PPDitit + α + α55DRGDRGitit + + αα66AGEAGEit it + α + α7 7 LOSLOSitit + α + α88DischargesDischargesitit + + Year + Year + λλii + + εεitit

HC is measured by percentage of RN hours provided by HC is measured by percentage of RN hours provided by RNs with at least a B.S. degree, RN age RNs with at least a B.S. degree, RN age (“experience”), RN tenure, and percentage of RN (“experience”), RN tenure, and percentage of RN hours provided by part-time RNs.hours provided by part-time RNs.


Summary StatisticsSummary StatisticsMeanMean Std. Dev.Std. Dev.

Failure to RescueFailure to Rescue 0.180.18 0.210.21 Rate of InfectionRate of Infection 0.00390.0039 0.0120.012 RN Hours Per Bed DayRN Hours Per Bed Day 19.5419.54 8.238.23 Patient AgePatient Age 65.8865.88 2.562.56 DRG WeightDRG Weight 1.741.74 0.510.51 Length of Stay in ICULength of Stay in ICU 13.913.9 1.281.28 % of RN Hours Provided by BS Degree or Higher% of RN Hours Provided by BS Degree or Higher 0.570.57 0.160.16 RN AgeRN Age 46.046.0 2.992.99 RN TenureRN Tenure 8.198.19 2.762.76 Number of DischargesNumber of Discharges 83.9983.99 47.8947.89

% of RN Hours Provided by Part-Time RNs% of RN Hours Provided by Part-Time RNs 0.0830.083 0.0770.077

Non-RN Hours Per Bed DayNon-RN Hours Per Bed Day 0.470.47 1.271.27


2006 average rate of failure to 2006 average rate of failure to rescue, by ICU bed sectionrescue, by ICU bed section2006 average rate of failure to rescue, by

ICU bed section

0

0.1

0.2

0.3

0.4

0.5

0.6

percentile

rate

of f

ailu

re to

resc

ue


2006 average rate of infection, by 2006 average rate of infection, by ICU bed sectionICU bed section2006 average rate of infection by ICU

bed section

00.0020.0040.0060.0080.01

0.0120.0140.0160.018

percentile

rate

of i

nfec

tion


Preliminary FindingsPreliminary FindingsGeneral human capital (education) is negatively General human capital (education) is negatively

correlated with the rate of infections due to correlated with the rate of infections due to medical caremedical care

Specific human capital (job tenure) is negatively Specific human capital (job tenure) is negatively correlated with the rate of infections due to correlated with the rate of infections due to medical care and rate of failure to rescue. The medical care and rate of failure to rescue. The former correlation holds even controlling for former correlation holds even controlling for nursing-unit fixed effects.nursing-unit fixed effects.

Data are only for intensive-care units and results are Data are only for intensive-care units and results are likely to be a lower bound on effects for more likely to be a lower bound on effects for more diverse units. diverse units.


Summary of OLS Results: Human Summary of OLS Results: Human Capital VariablesCapital Variables

General human capital (education) is negatively General human capital (education) is negatively correlated with the rate of infectionscorrelated with the rate of infections

Specific human capital (tenure) is negatively correlated Specific human capital (tenure) is negatively correlated with the rate of infections. A one standard deviation with the rate of infections. A one standard deviation increase in RN tenure is associated with a 19% increase in RN tenure is associated with a 19% decrease in rate of infectionsdecrease in rate of infections

Specific human capital (tenure) and failure to rescue Specific human capital (tenure) and failure to rescue are negatively correlated (though less robust). A one are negatively correlated (though less robust). A one standard deviation increase in RN tenure is associated standard deviation increase in RN tenure is associated with a 4% decrease in failure to rescue rate.with a 4% decrease in failure to rescue rate.


Summary of OLS Results: Other Summary of OLS Results: Other VariablesVariables

RN staffing has a negative but RN staffing has a negative but diminishing effect on infection rate, diminishing effect on infection rate, and is negatively correlated with and is negatively correlated with failure to rescue ratefailure to rescue rate

Non-RN hours has no effectNon-RN hours has no effectVery low patient volume is associated Very low patient volume is associated

with higher failure to rescue ratewith higher failure to rescue rate


Summary of Fixed Effects ResultsSummary of Fixed Effects Results

RN tenure negatively correlated with RN tenure negatively correlated with rate of infections and the measured rate of infections and the measured impact is more than twice as large as impact is more than twice as large as the OLS effect.the OLS effect.

RN tenure is insignificant in failure to RN tenure is insignificant in failure to rescue equation.rescue equation.

RN education is insignificant in both RN education is insignificant in both equations.equations.


Plans for Future WorkPlans for Future WorkExpand sample to include all acute-care unitsExpand sample to include all acute-care unitsControl for prior experience of RNsControl for prior experience of RNsControl for union membershipControl for union membershipStudy other measures of health care quality such as Study other measures of health care quality such as

30-day mortality rate, re-admission rates and 30-day mortality rate, re-admission rates and patient-assessed quality of carepatient-assessed quality of care

Add more information about human capital, Add more information about human capital, especially for off-shiftsespecially for off-shifts

Add information from RN satisfaction surveyAdd information from RN satisfaction surveyConstruct measures of team stability to study Construct measures of team stability to study

relational capitalrelational capital


Patient DataPatient Data 88% of the acute bedsection records link 88% of the acute bedsection records link

to only 1 IPD stay.to only 1 IPD stay.– 437,465 acute hospitalizations in FY 06437,465 acute hospitalizations in FY 06– 54,323 had more than 1 IPD stay mapped to 54,323 had more than 1 IPD stay mapped to

the same bedsection staythe same bedsection stay 94% of these had 2 IPDs94% of these had 2 IPDs 5.7% had 3 IPDs5.7% had 3 IPDs 0.3% had 4 or 5 IPDs0.3% had 4 or 5 IPDs


CorrelationsCorrelations fail rescue infections age drgwt los rn_bs rn hrs discharges rn tenure non-rn hrs parttime rn_age

fail rescue 1

infections -0.0149 10.4402

age -0.0348 -0.0117 10.0719 0.5322

drgwt 0.0234 0.0808 -0.0686 10.2269 0.0000 0.0002

los 0.1408 0.0385 -0.0339 0.4933 10.0000 0.0392 0.0692 0.0000

rn_bs 0.0056 0.0082 -0.1401 0.292 0.2087 10.7735 0.6625 0.0000 0.0000 0.0000

rn hrs -0.034 -0.0097 0.1354 -0.1218 -0.2144 -0.2256 10.0789 0.6027 0.0000 0.0000 0.0000 0.0000

discharges -0.0172 0.0303 -0.2819 0.4033 0.1313 0.3394 -0.3407 10.3741 0.1044 0.0000 0.0000 0.0000 0.0000 0.0000

rn tenure -0.0411 -0.0457 0.0972 -0.0331 -0.0096 -0.278 -0.0685 -0.1136 10.0338 0.0144 0.0000 0.0763 0.6078 0.0000 0.0002 0.0000

non-rn hrs 0.0564 -0.0311 0.0167 -0.1299 -0.0169 0.1147 0.2402 -0.14 -0.1644 10.0035 0.0960 0.3718 0.0000 0.3657 0.0000 0.0000 0.0000 0.0000

parttime -0.0293 0.0013 -0.0184 0.3022 0.0514 0.1993 0.0768 0.0955 -0.0807 -0.1366 10.1295 0.9465 0.3237 0.0000 0.0059 0.0000 0.0000 0.0000 0.0000 0.0000

rn_age 0.0243 -0.0284 0.0487 -0.2502 -0.0807 -0.351 -0.0712 -0.2258 0.5172 -0.1406 -0.2477 10.2092 0.1286 0.0091 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000


Rate of Infections, OLS RegressionsRate of Infections, OLS Regressions

Notes: N=2866 in columns (1) through (4). N=2821 in column 5. All regressions include dummy variablesfor quartiles of the number of discharges and year dummy variables.

(1) (2) (3) (4) (5)RN Hours Per Patient Day -0.000305** -0.000313*** -0.000313*** -0.000304** -0.000328***

(0.000119) (0.000119) (0.000118) (0.000119) (0.000120)Quadratic RN Hours Per Patient Day 0.00000594*** 0.00000596*** 0.00000596*** 0.00000581** 0.00000657***

(0.00000229) (0.00000229) (0.00000229) (0.00000230) (0.00000234)Patient Age -0.0000331 -0.0000165 -0.0000164 -0.0000176 -0.0000140

(0.0000891) (0.0000892) (0.0000892) (0.0000893) (0.0000903)DRG (diagnostic related group) weight 0.00191*** 0.00210*** 0.00209*** 0.00227*** 0.00187***

(0.000592) (0.000596) (0.000521) (0.000621) (0.000607)Length of Stay in ICU 0.000000402 -0.00000346 -0.0000284 0.0000532

(0.000205) (0.000205) (0.000206) (0.000206)% of RN Hours Provided by B.S. Degree or Higher -0.00197 -0.00278* -0.00279* -0.00256 -0.00288*

(0.00158) (0.00161) (0.00160) (0.00162) (0.00165)RN Age -0.000102 -0.00000336 -0.00000345 -0.0000149 -0.0000245

-0.000085 -0.0000936 -0.0000934 -0.0000943 -0.0000949RN Tenure -0.000253** -0.000253** -0.000248** -0.000255**

(0.000101) (0.000100) (0.000101) (0.000103)% of RN Hours Provided by Part-Timers -0.00310

(0.00310)Non-RN Hours Per Patient Day 0.0000766

(0.000377)Quadratic Non-RN Hours Per Patient Day -0.0000599

(0.0000527)


Failure to Rescue Rate, OLS RegressionsFailure to Rescue Rate, OLS Regressions

Notes: N=2673 in columns (1) through (4); N=2631 in column (5). All regressions include dummy variables for quartiles of discharges and dummy variables for years.

(1) (2) (3) (4) (5)RN Hours Per Patient Day -0.00303 -0.00324 -0.00416* -0.00309 -0.00286

(0.00225) (0.00225) (0.00226) (0.00225) (0.00227)Quadratic RN Hours Per Patient Day 0.0000511 0.0000526 0.0000573 0.0000505 0.0000395

(0.0000444) (0.0000443) (0.0000447) (0.0000444) (0.0000450)Patient Age -0.00326* -0.00290* -0.00293* -0.00292* -0.00277

(0.00169) (0.00170) (0.00171) (0.00170) (0.00171)DRG (diagnostic related group) weight -0.00736 -0.00408 0.0323*** -0.000626 -0.00413

(0.0108) (0.0109) (0.00966) (0.0114) (0.0111)Length of Stay in ICU 0.0269*** 0.0268*** 0.0264*** 0.0268***

(0.00387) (0.00386) (0.00389) (0.00388)% of RN Hours Provided by B.S. Degree or Higher 0.0101 -0.00624 0.0178 -0.00336 -0.0164

(0.0307) (0.0314) (0.0315) (0.0315) (0.0321)RN Age 0.00204 0.00376** 0.00448** 0.00351** 0.00397**

-0.00159 -0.00174 -0.00176 -0.00176 (0.00175RN Tenure -0.00457** -0.00466** -0.00446** -0.00416**


(0.0577)Non-RN Hours Per Patient Day 0.00838

(0.00698)Quadratic Non-RN Hours Per Patient Day 0.000276

(0.000972)


Rate of Infections Fixed EffectsRate of Infections Fixed Effects

Notes: N=2866 in columns (1) through (4). N=2821 in column (5). All regressions include dummy variables for quartiles of discharges and dummy variables for years.l

(1) (2) (3) (4) (5)RN Hours Per Patient Day -0.000356** -0.000357** -0.000357** -0.000357** -0.000321**

(0.000157) (0.000157) (0.000156) (0.000157) (0.000159)Quadratic RN Hours Per Patient Day 0.00000702** 0.00000710** 0.00000710** 0.00000710** 0.00000704**

(0.00000288) (0.00000288) (0.00000287) (0.00000288) (0.00000292)Patient Age -0.000261** -0.000262** -0.000262** -0.000262** -0.000240*

(0.000124) (0.000124) (0.000124) (0.000124) (0.000125)DRG (diagnostic related group) weight 0.0000941 0.000163 0.000180 0.000163 0.000184

(0.000921) (0.000921) (0.000842) (0.000922) (0.000928)Length of Stay in ICU -0.00000489 0.0000110 0.0000110 0.0000428

(0.000250) (0.000250) (0.000250) (0.000251)% of RN Hours Provided by B.S. Degree or Higher 0.000539 -0.000986 -0.000985 -0.000981 -0.00196

(0.00524) (0.00530) (0.00530) (0.00534) (0.00533)RN Age -0.000405 -0.000262 -0.000263 -0.000262 -0.000225

-0.000279 -0.000289 -0.000289 -0.000292 -0.000291RN Tenure -0.000529* -0.000528* -0.000529* -0.000595**

(0.000288) (0.000288) (0.000289) (0.000291)% of RN Hours Provided by Part-Timers 0.0000543

(0.00787)Non-RN Hours Per Patient Day -0.00153*

(0.000876)Quadratic Non-RN Hours Per Patient Day 0.0000238

(0.0000712)


Failure to Rescue Rate, Fixed EffectsFailure to Rescue Rate, Fixed Effects

Notes: N=2673 in columns (1) through (4). N=2631 in column (5). All regressions include dummy variables for quartiles of discharges and dummy variables for years.

(1) (2) (3) (4) (5)RN Hours Per Patient Day -0.00351 -0.00351 -0.00405 -0.00353 -0.00367

(0.00299) (0.00300) (0.00299) (0.00300) (0.00304)Quadratic RN Hours Per Patient Day 0.0000710 0.0000710 0.0000773 0.0000713 0.0000670

(0.0000560) (0.0000560) (0.0000561) (0.0000561) (0.0000568)Patient Age -0.000214 -0.000211 0.0000642 -0.000199 -0.000151

(0.00241) (0.00241) (0.00241) (0.00241) (0.00242)DRG (diagnostic related group) weight 0.0191 0.0191 0.0378** 0.0193 0.0145

(0.0172) (0.0172) (0.0157) (0.0172) (0.0173)Length of Stay in ICU 0.0129*** 0.0129*** 0.0129*** 0.0141***

(0.00479) (0.00480) (0.00480) (0.00481)% of RN Hours Provided by B.S. Degree or Higher -0.139 -0.137 -0.139 -0.141 -0.140

(0.102) (0.103) (0.103) (0.104) (0.104)RN Age -0.00118 -0.00134 -0.00175 -0.00151 -0.000964

-0.00524 -0.00546 -0.00546 -0.0055 -0.00548RN Tenure 0.000592 0.00115 0.000718 -0.000489


(0.148)Non-RN Hours Per Patient Day -0.00693

(0.0170)Quadratic Non-RN Hours Per Patient Day 0.00248*

(0.00134)

human capital in the nursing workforce and its impact on patient outcomes

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