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Rehab Measures: Activity Measure for Post Acute Care

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For more information on the AM-PAC, click here. 

Title of Assessment

Activity Measure for Post Acute Care 

Acronym

AM-PAC

Instrument Reviewer(s)

Initially reviewed by Jason Raad and the Rehabilitation Measures Team; Updated by Tammie Keller Johnson PT, DPT, NCS and and the TBI EDGE task force of the Neurology section of the APTA in September 2012

Summary Date

3/1/2013 

Purpose

Assesses activity limitations based on World Health Organization’s International Classification of Functioning, Disability and Health (ICF).
 
The Computer Adaptive Test (CAT) version of the AMPAC selects items designed to match a patient’s functional abilities, reducing the total number of items on the assessment while increasing the measure's validity.
 
Conversion tables to CMS G-codes are available for all AM-PAC scales.

Description

Patient or clinician reported measure

In each domain, AM-PAC scores have a mean of 50 and a standard deviation of 10

AM-PAC Activity Domains:

Applied Cognitive

Personal & Instrumental/Daily Activity

Movement & Physical/Basic Mobility

Communication

Grooming and Hygiene

Bend/Stand/Carry

Print Information

Feeding and Meal Prep

Ambulation

New Learning

Dressing

Transfers

Social

Instrumental

WC Skills

Area of Assessment

Activities of Daily Living; Cognition; Functional Mobility 

Body Part

Not Applicable 

ICF Domain

Activity 

Domain

ADL; Cognition; Motor 

Assessment Type

Patient Reported Outcomes 

Length of Test

 

Time to Administer

Varies depending on AM-PAC version used; As a Computer Adaptive Test (CAT), the time to administer will slightly vary between patients.

Number of Items

As a CAT, the number of items will vary, Typically 5 to 8 items per domain; Inpatient short form contains 6 items per domain; Outpatient short form contains 15-18 items per domain 

Equipment Required

  • Computer adaptive test
  • Paper and Pencil for in-patient and out-patient short forms

Training Required

Training available

Type of training required

Reading an Article/Manual 

Cost

Not Free 

Actual Cost

The AM-PAC is available in either a paper and pencil or computer adaptive version.
 
AM-PAC is free for academic research use; there is a charge for clinical/commercial use
 
 

Age Range

Adult: 18-64 years; Elderly adult: 65+ 

Administration Mode

Computer 

Diagnosis

 

Populations Tested

The AM-PAC is validated for use with post acute care patients with major medical, orthopedic, and neurologic impairments
 
Has been tested in many mixed populations including:
  • inpatient rehabilitation
  • post-acute care
  • hip fracture
  • spine
  • lower extremity impairments
  • upper extremity impairments
  • medically complex cases
  • geriatric
  • neurological patients (e.g., stroke)
  • cancer

Standard Error of Measurement (SEM)

AM-PAC Computer Adaptive Test (CAT): (Jette et al, 2007; n = 1815 retrospective study; patients diagnosed with spine, lower-extremity, and upper-extremity impairments)
 
Average Standard Error of Estimate by Ability Score:
Scale

Score Range

10-29
30-49
50-69
70-90
Basic Mobility; Mean S.E. 
4.45
2.16
1.99
3.19
95% C.I.
+/- 8.72
+/- 4.23
+/- 3.90
+/- 6.25
Daily Activity; Mean S.E.

2.60

1.98

5.32

N/A

95% C.I.

+/- 5.10

+/- 3.88

+/- 10.43

N/A

C.I. = Confidence Interval
S.E. = Standard Error of Measurement

Minimal Detectable Change (MDC)

AM-PAC Computer Adaptive Test (CAT): (Jette et al, 2007)
  • Basic Mobility: MDC = 4.28
  • Daily Activity: MDC = 3.70
  • Applied Cognitive: MDC90 = 5.55

Minimally Clinically Important Difference (MCID)

Not Established

Cut-Off Scores

Not Established

Normative Data

Patients with Hip Fracture: (Latham et al, 2008; n = 108; patients aged 65 or older; assessed within 17 days of surgical repair of a unilateral hip fracture; International Sample)
 
AM-PAC and Related Measure Norms:
AM-PAC Physical Mobility
mean (SD)
median (range)
    Baseline
48.0 (10.0)

51.9 (19.2–62.7)

    Week 12
59.7 (8.2)

60.2 (29.0–82.5)

AM-PAC Personal Care
mean (SD)
median (range)
    Baseline
49.2 (8.0)

48.5 (22.0–68.0)

    Week 12
57.0 (8.8)
58.2 (35.0–68.1)
PFP-10
mean (SD)
median (range)
    Baseline
10.4 (9.9)
6.8 (0–45.2)
    Week 12
24.5 (18.4)
21.3 (0–78.1)
SPPB
mean (SD)
median (range)
    Baseline

4.7 (2.8)

5.0 (0–12.0)

    Week 12

7.9 (2.6)

8.0 (0–12.0)

Gait speed (m/s)
mean (SD)
median (range)
    Baseline

0.50 (0.28)

0.45 (0.01–1.33)

    Week 12

0.77 (0.35)

0.76 (0.003–1.83)

6MWT (m)
mean (SD)
median (range)
    Baseline

121.0 (103.0)

109.6 (0–408.1)

    Week 12

251.0 (155.5)

259.0 (0–651.9)

SF-36 PF
mean (SD)
median (range)
    Baseline

23.0 (21.8)

15.0 (0–90.0)

    Week 12

57.5 (25.5)

57.5 (0–100)

Orthopedic outpatient: Individuals with spine, lower-extremtiy and upper extremity impairments: (Jette et al, 2007; n = 1815 seen in outpatient clinics)

Domain

n

Admission

Mean (SD)

Discharge

Mean (SD)

Total

1703

63.26 (9.19)

68.71 (8.41)

Spine

666

63.57 (7.78)

68.40 (8.59)

EU

462

68.42 (8.24)

71.20 (7.74)

LE

575

58.75 (9.16)

67.07 (8.26)

Test-retest Reliability

Postacute Care Patients: (Andres et al, 2003; n = 25; mean age = 65.0 (range = 23-87) years; Impairments, Neurologic = 32%, Orthopdedic = 32%, Medically complex = 36%; mean time between assessments = 2.7 to 3.5 (range 1 to 7) days)
 
Test-retest Reliability:

Strength

ICC
95% CI
Personal and instrumental
Excellent
0.96
0.92–0.98
Movement and physical
Excellent
0.97
0.92–0.98
Applied cognition
Excellent
0.91
0.70–0.96
CI = Confidence Interval

Interrater/Intrarater Reliability

Postacute Care Patients: (Andres et al, 2003; proxy = primary physical, occupational therapist or family member)
 
Interrater Reliability:

Strength

ICC
95% CI
Personal and instrumental
Excellent
0.90
0.73–0.94
Movement and physical
Excellent
0.86
0.68–0.96
Applied cognition
Adequate
0.68
0.55–0.89
CI = Confidence Interval

Internal Consistency

Not Established

Criterion Validity (Predictive/Concurrent)

Patients with Hip Fracture(Latham et al, 2008)
 
Adequate to Excellent convergent validity (see below)
 
Performance-Based and Self-Report Function Measure Correlations* at Week 12
AM-PAC Physical Mobility
AM-PAC Personal Care
SF-36 PF
PFP-10
SPPB Total
Gait Speed Value
6MWT
AM-PAC Physical Mobility
1
0.71
0.84
0.64
0.65
0.65
0.67
AM-PAC Personal Care
1
0.68
0.63
0.55
0.49
0.61
SF-36 PF
1
0.69
0.67
0.68
0.73
PFP-10
1
0.73
0.80
0.85
SPPB Total
1
0.84
0.75
Gait Speed Value
1
0.82
6MWT
1
r < .31 = Poor
r .31 to .59 = Adequate
r > .6 = Excellent
SF-36 PF = Medical Outcomes Study 36-Item Short Form Health Survey Physical Function Scale
PFP-10 = Physical Functional Performance Test
SPPB = Short Physical Performance Batter
6MWT = Six-Minute Walk Test
*Spearman Correlations

Construct Validity (Convergent/Discriminant)

AM-PAC Computer Adaptive Test (CAT): (Jette et al, 2007)
  • Significant differences in basic mobility were observed in the subject’s acuity level and surgical status.
AM-PAC Difference Scores for Basic Mobility and Daily Activity: 
Scale
Acuity
Postsurgical Treatment

Basic Mobility

< 35 days
> 35 days
Difference
Yes
No
Difference

Admission

63.45 (9.39)

62.85 (9.63)

0.60

59.00 (10.14)

64.69 (8.37)

-5.70*

Discharge

70.11 (8.17)

68.14 (8.30)

1.97*

66.73 (7.79)

69.34 (8.52)

-2.61*

Increase

6.62 (8.60)

5.22 (7.94)

1.40*

7.85 (8.62)

4.65 (7.57)

3.20*

Daily Activity

< 35 days
> 35 days
Difference
Yes
No
Difference

Admission

56.31 (8.28)

56.18 (8.43)

0.13

54.32 (8.19)

57.88 (7.67)

-3.56*

Discharge

61.85 (5.96)

60.12 (7.06)

1.73*

60.70 (6.67)

60.95 (6.50)

-0.25

Increase

5.53 (7.60)

3.89 (6.95)

1.64*

6.38 (8.10)

3.07 (6.24)

3.31*

*p < 0.05

Content Validity

The AM-PAC was developed using the World Health Organization’s International Classification of Functioning, Disability and Health (ICF).

Face Validity

Items for the original prototype of the AM-PAC were created based on the ICF activities domain. Items relevant to individuals in post-acute care setting were chosen. The items were reviewed by 10 experts and feedback was provided by individuals with disabilities. (Haley et al., 2004)

Many items were selected from existing legacy measures.

Floor/Ceiling Effects

Rehabilitation Patients: (Coster et al, 2006; n = 516; mean age = 68.3 (14.97) years; data collected at 1, 6, and 12 months after discharge)

  • Excellent: No floor effects were observed across 3 assessments
  • Adequte: Physical and Movement Activity scales demonstrated low ceiling effects (less than 1% at 12 months)
  • Adequate: Personal Care and Instrumental scales had higher ceiling effects (16% at 12 months)
  • Poor: Applied Cognitive scale demonstrated the largest ceiling effects (27% at 1 month; 44% at 12 months)

Responsiveness

Rehabilitation Patients: (Coster et al, 2006)
  • Standard Response Means between 3 diagnostic groups (neurological, orthopedic, complex medical) ranged between -0.02 and 0.10 (small)
  • Mean positive changes ranged from 8.35 to 13.23 points from 1 to 6 months
  • Mean positive changes ranged from 4.64 and 7.56 points from 6 to 12 months

Orthopedic outpatient: Individuals with spine, lower-extremtiy and upper extremity impairments (Jette et al, 2007; n = 1815 seen in outpatient clinics)

Domain

n

Difference

Effect Size

SRM

Total

1703

5.45 (7.97)

0.59

0.68

Spine

666

4.83 (7.56)

0.62

0.64

EU

462

2.78 (6.87)

0.34

0.40

LE

575

8.32 (8.35)

0.91

1.00

Professional Association Recommendations

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (VEDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

 

For detailed information about how recommendations were made, please visit:  http://www.neuropt.org/go/healthcare-professionals/neurology-section-outcome-measures-recommendations

 

Abbreviations:

HR

Highly Recommend

R

Recommend

LS / UR

Reasonable to use, but limited study in target group  / Unable to Recommend

NR

Not Recommended

 

Recommendations based on level of care in which the assessment is taken:

 

Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility

Outpatient

Rehabilitation

Home Health

TBI EDGE

NR

LS

LS

NR

NR

 

 

Recommendations for use based on ambulatory status after brain injury:

 

Completely Independent

Mildly dependant

Moderately Dependant

Severely Dependant

TBI EDGE

N/A

N/A

N/A

N/A

 

 

Recommendations for entry-level physical therapy education and use in research:

 

Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)

TBI EDGE

No

No

Yes

Not reported

Considerations

  • Can be administered with either a paper and pencil or computer based version
  • Accurate scoring can be obtained from either the setting-specific short form versions or Computer Adaptive Testing forms.
  • Recent work using patient-reported outcomes suggests that a short-form version of the Activity Measure for Post-Acute Care (AM-PAC) may be more sensitive than the FIM in assessing functional gains and losses once a patient returns to the community (Coster et al, 2006).
  • Haley et al, 2006, reported that fewer items (33%) and less time (44%) is required to complete the AM-PAC-CAT than the AM-PAC-66 (short form).
Do you see an error or have a suggestion for this instrument summary? Please e-mail us!

Bibliography

Andres, P. L., Haley, S. M., et al. (2003). "Is patient-reported function reliable for monitoring postacute outcomes?" Am J

Coster, W. J., Haley, S. M., et al. (2006). "Measuring patient-reported outcomes after discharge from inpatient rehabilitation settings." J Rehabil Med 38(4): 237-242. Find it on PubMed

Haley, S. M., Coster, W. J., et al. (2004). "Activity outcome measurement for postacute care." Med Care 42(1 Suppl): I49-61. Find it on PubMed

Haley, S. M., Ni, P., et al. (2009). "Replenishing a computerized adaptive test of patient-reported daily activity functioning." Qual Life Res 18(4): 461-471. Find it on PubMed

Haley, S. M., Siebens, H., et al. (2006). "Computerized adaptive testing for follow-up after discharge from inpatient rehabilitation: I. Activity outcomes." Arch Phys Med Rehabil 87(8): 1033-1042. Find it on PubMed

Jette, A. M., Haley, S. M., et al. (2007). "Prospective evaluation of the AM-PAC-CAT in outpatient rehabilitation settings." Phys Ther 87(4): 385-398. Find it on PubMed

Latham, N. K., Mehta, V., et al. (2008). "Performance-based or self-report measures of physical function: which should be used in clinical trials of hip fracture patients?" Arch Phys Med Rehabil 89(11): 2146-2155. Find it on PubMed

Year published

2002 

Instrument in PDF Format

Yes 
Approval Status Approved 
 
Attachments
Created at 4/4/2011 9:41 AM  by Jason Raad 
Last modified at 8/28/2014 2:56 PM  by Jason Raad