Patient turnover and nursing staff adequacy

Health Services Research, April, 2006 by Lynn Y. Unruh, Myron D. Fottler

Table 1: Average Patient Length of Stay, Patient Turnover,
Turnover Indices, Severity, and Severity Index in Pennsylvania
Hospitals 1994-2001

                               1994    1995    1996    1997

Average patient length of stay
  Mean                         6.32    5.96    5.67    5.50
  Standard deviation           1.67    2.23    2.21    1.90
  % [DELTA] from prior year     --    -4.46   -5.04   -2.41
Patient turnover
  Mean                         0.17    0.18    0.19    0.19
  Standard deviation           0.03    0.03    0.04    0.04
  % [DELTA] from prior year     --     6.97    6.05    2.98
Turnover index 1 *
  Mean                         1.00    1.07    1.14    1.18
  Standard deviation           0       0.10    0.13    0.17
  % [DELTA] from prior year     --     6.97    6.27    2.98
Turnover index 2 ([dagger])
  Mean                         1.00    1.04    1.07    1.08
  Standard deviation           0       0.04    0.05    0.07
  % [DELTA] from prior year     --     3.56    2.96    1.37
Patient severity score
  Mean                         1.12    1.15    1.11    1.17
  Standard deviation           0.22    0.25    0.25    0.27
  % [DELTA] from prior year     --     2.82   -1.86    8.75
Severity index
  Mean                         1.00    1.03    1.00    1.07
  Standard deviation           0       0.13    0.16    0.32
  % [DELTA] from prior year     --     2.78   -1.77    8.61

                                                              % [DELTA]
                               1998    1999   2000    2001    1994-2001

Average patient length of stay
  Mean                         5.26    0.50   4.90    4.87       --
  Standard deviation           2.00    2.03   1.04    0.97       --
  % [DELTA] from prior year   -4.16   -2.47  -1.88   -1.73     -20.84
Patient turnover
  Mean                         0.20    0.20   0.21    0.22       --
  Standard deviation           0.04    0.04   0.04    0.04       --
  % [DELTA] from prior year    4.73    1.45   2.65    2.42      29.43
Turnover index 1 *
  Mean                         1.23    1.24   1.28    1.29       --
  Standard deviation           0.16    0.17   0.16    0.19       --
  % [DELTA] from prior year    4.70    1.34   3.24    1.20      29.43
Turnover index 2 ([dagger])
  Mean                         1.11    1.11   1.13    1.13       --
  Standard deviation           0.06    0.07   0.07    0.08       --
  % [DELTA] from prior year    2.33    0.69   1.40    0.23      13.26
Patient severity score
  Mean                         1.39    1.40   1.32    1.23       --
  Standard deviation           0.21    0.23   0.22    0.19       --
  % [DELTA] from prior year   23.56    1.04  -5.49   -6.11       9.8
Severity index
  Mean                         1.31    1.31   1.25    1.16       --
  Standard deviation           0.56    0.57   0.51    0.49       --
  % [DELTA] from prior year   23.70    0.99  -5.56   -6.16      15.66

* Turnover index 1 uses 1 /LOS.

([dagger]) Turnover index 2 uses square root (1/LOS).

Table 2: RN/1,000 APDC in Pennsylvania Hospitals 1994-2001,
before and after Adjustment for Patient Turnover and Severity

                      1994         1995          1996         1997

Before adjustment
  RN/1,000 APDC       2.84         2.88          2.94         2.92

After adjustment for patient turnover ([dagger])
  RN/1,000
    APDC (adj)        2.84         2.75          2.65         2.54
  Mean difference     0           -0.14         -0.29        -0.37
  t-Value             --          -3.00 *       -5.82 ***    -8.11 ***

After adjustment for patient turnover ([double dagger])
  RN/1,000
    APDC (adj)        2.84         2.80          2.78         2.71
  Mean difference     0           -0.10         -0.18        -0.22
  t-Value             --         -12.45 ***    -14.66 ***   -17.18 ***

After adjustment for patient turnover ([dagger]) and severity
  RN/1,000
    APDC (adj)        2.86         2.71          2.71         2.51
  Mean difference     0           -0.19         -0.23        -0.41
  t-Value             --          -3.43 ***     -4.18 ***    -6.92 ***

After adjustment for patient turnover ([double dagger]) and severity
  RN/1,000
    APDC (adj)        2.86         2.75          2.81         2.68
  Mean difference     0           -0.14         -0.11        -0.25
  t-Value             --          -5.31 ***     -3.42 ***    -5.39 ***

                      1998         1999          2000         2001

Before adjustment
  RN/1,000 APDC       2.89         2.88          2.86         2.81

After adjustment for patient turnover ([dagger])
  RN/1,000
    APDC (adj)        2.43         2.37          2.29         2.26
  Mean difference    -0.47        -0.51         -0.6         -0.62
  t-Value            -8.64 ***    -11.14 ***   -20.17 ***   -23.21 ***

After adjustment for patient turnover ([double dagger])
  RN/1,000
    APDC (adj)        2.63         2.61          2.58         2.56
  Mean difference    -0.28        -0.29         -0.32        -0.33
  t-Value           -19.47 ***   -18.75 ***    -20.18 ***   -22.60 ***

After adjustment for patient turnover ([dagger]) and severity
  RN/1,000
    APDC (adj)        1.96         1.93          1.20         2.09
  Mean difference    -0.95        -0.98         -0.92        -0.8
  t-Value           -23.68 ***   -24.46 ***    -21.61 ***   -20.44 ***

After adjustment for patient turnover ([double dagger]) and severity
  RN/1,000
    APDC (adj)        2.16         2.23          2.28         2.43
  Mean difference    -0.75        -0.81         -0.68        -0.56
  t-Value           -20.86 ***   -16.60 ***    -18.33 ***   -12.40 ***

* p < .01.

** p < .001.

*** p < .0001.

([dagger]) Turnover adjustment 1 uses 1/LOS.

([double dagger]) Turnover adjustment 2 uses square root(1/LOS).

Table 3: Percentage Change in RN/1,000 APDC in Pennsylvania Hospitals
1994-2001, before and after Adjustment for Patient Turnover and Severity

                      1994-5       1995-6       1996-7       1997-8

Before adjustment
  RN/1,000 APDC     2.25         1.61          -0.27        -0.58

After adjustment for patient turnover ([dagger])
  RN/1,000
    APDC (adj)       -3.98        -3.77        -1.78        -3.56
  Mean difference    -6.54        -5.48        -1.47        -3.26
  t-Value           -13.13 ***   -10.65 ***    -4.69 ***    -8.57 ***

After adjustment for patient turnover ([double dagger])
  RN/1,000
    APDC (adj)       -0.97        -0.68        -1.23        -1.58
  Mean difference    -3.33        -2.86        -1.25        -1.23
  t-Value           -13.19 ***   -10.95 ***    -4.79 ***    -8.82 ***

After adjustment for patient turnovers and severity
  RN/1,000
    APDC (adj)       -6.02         0.04        -7.07       -17.69
  Mean difference    -8.57        -1.25        -7.04       -17.71
  t-Value            -9.43 ***    -1.04        -6.21 **    -14.36 ***

After adjustment for patient turnovers and severity
  RN/1,000
    APDC (adj)       -2.24         3.35        -4.87       -15.95
  Mean difference    -4.77         1.58        -5.16       -15.77
  t-Value            -4.58 ***     1.33        -5.35 ***   -13.68 ***

                      1998-9      1999-00      2000-01      1994-01

Before adjustment
  RN/1,000 APDC      -0.17        -1.86       -2.09         -1.26

After adjustment for patient turnover ([dagger])
  RN/1,000
    APDC (adj)       -1.47        -3.58       -1.31        -20.23
  Mean difference    -1.1         -2.24        0.66        -19.51
  t-Value            -2.20 *      -4.53 ***    1.34        -23.84 ***

After adjustment for patient turnover ([double dagger])
  RN/1,000
    APDC (adj)       -0.23        -2.30       -0.73        -10.41
  Mean difference    -0.65        -1.11        1.31         -9.51
  t-Value            -2.78 **     -4.61 ***    1.32        -23.07 ***

After adjustment for patient turnovers and severity
  RN/1,000
    APDC (adj)       -1.30         2.13        5.95        -26.49
  Mean difference    -1.09         3.59        6.14        -25.97
  t-Value            -3.11 **      5.17 ***    7.84 ***    -20.35 ***

After adjustment for patient turnovers and severity
  RN/1,000
    APDC (adj)       -0.51         2.98        6.30        -16.50
  Mean difference    -0.42         4.82        6.52        -15.55
  t-Value            -2.57         8.99 ***   11.03 ***    -14.13 ***

* p < .01.

** p < .001.

*** p < .0001.

([dagger]) Turnover adjustment 1 uses 1/LOS.

([double dagger]) Turnover adjustment 2 uses square root(1/LOS).

Table 4: Comparison of Study Findings to Graf et al. (2003) Case Study

                                        Turnover          Turnover
                      Graf et al.     Adjustment 1      Adjustment 2
                       (2003) (%)     (1/LOS) (%)     Sqrt (1/LOS) (%)

Percent                    22              21                21
  change in LOS
Percent                    19              20                10
  change RN
  staffing
  or workload
Increase                   90              95                48
  in RN staffing
  as a proportion
  of increase in
  length of stay

                        Turnover           Turnover
                      Adjustment 1       Adjustment 2
                    and Severity (%)   and Severity (%)

Percent                    21                 21
  change in LOS
Percent                    26                 16

  change RN
  staffing
  or workload
Increase                  124                 76
  in RN staffing
  as a proportion
  of increase in
  length of stay

Sqrt, square root.