JAGS 38:1311-1315, 1990
The Nursing Home Life-Space Diameter A Measure of Extent and Frequency of Mobility Among Nursing Home Residents M a y E. Tinetti, MD, and Sandra F. Ginter, RN We developed the Nursing Home Life-Space Diameter (NHLSD) as a measure of the extent and frequency of mobility among skilled nursing facility (SNF) residents. lntrarater and interrater reliability was assessed in a small sample of SNF residents. The means and ranges of NHLSD scores, the characteristics associated with NHLSD score, and the association between NHLSD score and other functional characteristics were then determined among 398 residents of 12 SNFs. NHLSD scores ranged from 0, signifying bed- or chair-bound to 50, signifying leaving the facility daily. The correlation between NHLSD scores by two nurses was 0.951; the correlation between scores
at two points of time was 0.922. Mean score among the 398 subjects was 27.05. Decreased vision, presence of a neurologic disease, and arthritis were all associated with lower NHJSD score. Mobility (NHLSD) score was moderately correlated with other functional characteristics such as participation in social activities (Spearman’s correlation = +0.565). The NHLSD, which represents a simple and reliable assessment of mobility among SNF residents, could be used to assess the effect of interventions and to monitor changes among SNF residents. J Am
M
nit^.^ Finally, staff members are often available to aid in mobility if residents are not completely independent. The unique features of the nursing home need to be considered in assessing function, and specifically mobility, in this setting. Recently, we embarked on an observational study of the impact of mechanical restraint use among SNF residents. We felt that a careful assessment of activity level was essential to describing the total impact of mechanical restraint use. In the nursing home, as in the community, participation in higher-level social and physical activities can vary a great deal from individual to individual and depends on factors such as personal preference, past experience, and gender.j.4 We felt therefore, that assessment of extent and frequency of mobility would represent an optimal measure of activity level. In general, the farther, and more often, an individual moves around within and outside the facility, the more physical and/or social activities he or she is likely to engage in. Instruments are available for measuring dependence, or amount of assistance needed, in transfers, ambulation, and wheelchair m ~ b i l i t y . Other ~ , ~ instruments assess, either by simple observation or through techniques such as videotapes, the safety and effectiveness of specific componentsof balance and Measurements of extent of movement that categorize residents into “bedbound,” ”bed to chair,” or “ambulatory” groups or mild, moderate, or severe im-
aneuvering through the environment is central to functioning. Basic activities of daily living (ADLs) such as eating, dressing, bathing, and toileting all require at least some movement.’ Participation in higher-level social and physical activities obviously depends on traveling to the location of these activities. Although the dependence of functioning on mobility is true in the community as well as in nursing homes, movement within institutions has several unique features. First, the places to which residents are likely to travel, such as dining rooms, recreational areas, and nurses’ stations, are more limited and defined; all residents travel to the same location for the same activity. Second, the environment usually is adapted for frail persons by incorporating features such as non-skid floors,railings along walls, and alternatives to stairs. In addition, nursing homes, at least skilled nursing facilities (SNFs),are adapted for wheelchair mobility, a mode of personal mobility used more commonly in nursing homes than in the commu-
~
From the Department of Medicine, Yale University School of Medicine, New Haven, Connecticut. Supported in part by a grant from the Cox Foundation. Dr.Tmetti was supported in part by an N.I.A. academic award. Address correspondence and reprint requests to Mary E. Tinetti, MD, Department of Medicine, Yale University School of Medicine, P.O.Box 3333,333 Cedar Street, New Haven, CT 06510. 0 1990 by the American Geriatn’cs Society
Geriatr SOC38:1311-1315,1990
0002-8614/90/$3.50
1312 TINETTI AND GINTER
pairment, although available, may not capture the spectrum of mobility possible or may not be sensitive to clinically relevant amounts of change.lOJ1We adapted the Life-Space Diary to the nursing home setting, therefore, in order to capture the full spectrum of movement possible among SNF residents. The Life-Space Diary, based on the concept of lifespace diameter, was recently developed to measure extent and frequency of mobility in elderly persons living in the community.12 ”Life space” refers to the area throughout which an individual moves during a set period of time. The life space, in this recent report, was divided into concentric zones including the bedroom, the rest of the home, the grounds surrounding the home, the block in which the home was located, and the area beyond a traffic-bearing street. The concept of life space seemed ideal for use in the nursing home setting, which also includes readily recognizable zones. The aims of the present study were: (1)to develop an instrument to measure extent and frequency of mobility among SNF residents based on the concept of life-space diameter; (2) to test the reliability of this instrument; (3) to identify factors associated with amount of movement; (4) to correlate life-space mobility with other functional measures such as basic activities of daily living and participation in social activities; and (5) to assess the spectrum of mobility in multiple SNFs.
METHODS Based on the intended purpose and use, we determined that the mobility instrument would need to fulfill the following requirements: (1)it could be used in a large number of SNF residents residing in several different homes (i.e., instrument should be generalizable); (2) it would be sensitive to clinically relevant changes in mobility; (3) it could be used for residents whose mode of transportation was either walking or wheeling a wheelchair; (4) it correlated with other functional outcomes such as participation in social activities; and (5) it could be completed reliably by multiple observers. The last criterion was felt to be necessary because self-report is not reliable from cognitively impaired SNF residents, and residents are cared for by many staff members.
IAGS-DECEMBER 1990-VOL 38, N O . 12
TABLE 1. WORDING AND SCORING OF THE NURSING HOME LIFE-SPACE DIAMETER (Within the last 2 weeks, how often has moved around,. . . . . . ?) Diameter 1, Within his or her own room 2, Outside the room, within the unit 3, Outside the unit, throughout the facility 4, Outside the facility (i.e., left the facility) Frequency Would yousay . . . 5, > 3 times a day 4 , 1 - 3 times a day 3, > 2 times a week 2, At least weekly 1, Less than weekly 0, Never
+
NHLSD = 1 (diameter 1 X frequency 1) 2 (diameter 2 X frequency + 3 (diameter 3 X frequency 3) 4 (diameter 4 X frequency a). lndependence of movement can be incorporated into score by multiplying by 2 if movement was done without human assistance. 2)
+
Breaking frequency down further, for example, by number of trips daily, although improving sensitivity of the NHLSD, would compromise reliability. Two weeks was chosen as the time frame to reflect a reasonable period of time during which staff recall could be considered reliable and during which major changes within an individual’s habits would be infrequent. Independence, referring to whether the resident was able to maneuver alone or required human assistance, was added as an optional component. In order to ensure understanding of the concept and questions, to select optimal wording, and to ensure ease of administration a preliminary instrument was reviewed by several nurses. Based on this review, minor changes in wording were made. The final instrument, with scoring, is shown in Table 1.
First Phase: Reliability Testing The NHLSD was subjected to interrater and intrarater reliability testing. The subjects included residents at three New Haven nursing homes. A nurse research assistant randomly selected every tenth chart off the rack. Excluding subDevelopment of the Nursing Home Life-Space Di- jects who were bed- or chair-bound or restrained, she ameter A preliminary Nursing Home Life-Space Diam- reviewed charts until 25 residents, including nine males eter (NHLSD) was developed, which included compo- and 16 females, were enrolled. The average age of subnents of frequency and extent of mobility. Extent of jects was 82 years (range, 69 -93). mobility was measured by dividing the nursing home The nurse-researcher administered the NHLSD to the into the following logical zones: the resident’s room, the two nurses most involved in each subject‘s care during unit or nursing station on which the resident resides, the the day shift. Day-shift staff members were chosen berest of the facility beyond the unit, and any area outside cause this is the time during which most mobility and the facility. For ease of administration, frequency was activity occurs. The nurse-researcher returned 10 to 14 broken down to categories of more than three times a days later and readministered the instrument to one of the nurses. Correlation coefficients were determined for day, one to three times a day, more than two times a week, at least weekly, less than weekly, and never. the NHLSD scores. ~~
JAGS-DECEMBER 1990-VOL 38, NO. 12
Second Phase: NHLSD in 12Skilled Nursing Facilities The purposes of the second phase were to describe the means and ranges of the NHLSD score in different SNFs; to describe factors associated with NHLSD score; and to correlate the NHLSD score with other functional characteristics. Subjects were all residents at 12 New Haven area SNFs. Of the 1,798 residents at these 12 homes, 43 were excluded because they were less than 60 years of age; 1,041 because they had been mechanically restrained in the previous 2 weeks, thus not allowing independent mobility; and 31 6 because they were not independent with transfers. Three hundred ninetyeight subjects were included in the second phase of the NHLSD testing. The nurse-researcher extracted demographic and medical data on each subject from the SNF chart. Level of dependence in activities of daily living and participation in social activities were ascertained from the head nurse on each unit. Individual activities of daily living, including eating, dressing, bathing, and toileting were scored from 0, which indicated that the subject required total assistance, to 3, which indicated that subject was completely independent. Frequency of participation in social activities sponsored by the SNF was scored on a five-level scale from 0 (never) to 4 (daily). The NHLSD was administered to the head nurse on each SNF unit. The formula used to calculate score is shown in Table 1. Means and ranges for the NHLSD were determined for the total sample as well as for each of the 12 SNFs. After dichotomizing continuous independent variables such as age, Student's t-tests were performed. Multiple linear regression was then performed to identify the independent predictors of NHLSD score. Finally, association between NHLSD score and level of social participation and ADL functioning were determined using Spearman's correlations. RESULTS First Phase The wording and scoring of the Nursing Home Life-Space Diameter (NHLSD) are shown in Table 1. Although possible scores ranged from 0, referring to complete bedrest, to 50, referring to leaving the facility daily, no subject scored zero because bed-bound residents were excluded. If independence of movement was incorporated into the score by multiplying by two, the maximum possible score increased to 100. Unless stated otherwise, the following scores do not include the component of independence. The mean NHLSD score among the 25 subjects was 26.2 f 9.2 (mean f SD). Scores ranged from 1 to 42 without including independence and from 2 to 76 including independence. The correlationbetween the NHLSD scores of the two nurses at time 1 was .951 (Pearson's correlation). The correlation between scores at times 1 and 2 was .922. The correlations were similar when independence was incorporated into the score.
MOBILITY AMONG NURSING HOME RESIDENTS 1313
TABLE 2. NURSING HOME LIFE-SPACE DIAMETER SCORES AT 12 SKILLED NURSING FACILITIES NHLSD Score Facility
No. of Subjects
Mean f SD
1 2 3 4 5 6 7 8 9 10 11 12
86 21 23 22 18 18 73 52 13 10 37 25
23.1 f 8.9 31.3f 9.2 29.5 f 8.9 28.9 f 10.0 30.3 f 5.4 17.6 k 8.7 25.9 f 10.1 22.8f 7.5 30.2 f 11.0 33.6 f 8.5 36.7f 8.5 32.0k 8.4
Total
398
Range
5-46 11 -46
7-42 9-46 15-42 5-35 5-50 5-42 4-46 15-42 5-50 15-43
\
27.1 f 10.0
4-50
Second Phase The overall mean NHLSD for the 398 subjects included in the second phase testing was 27.1 k 10.2, with a range of 4 to 50. The range including independence was 4 to 78. The means, standard deviations, and ranges of scores for the 12 SNFs are listed in Table 2. The associations between resident characteristics and amount of mobility are shown in Table 3. Mobility was not associated with age or sex of the residents, with TABLE 3. CHARACTERISTICS OF SUBJECTS ACCORDING TO NHLSD SCORE (n = 398)
Characteristic
Age 580 years >80 years Sex Female Male Decreased vision YeS
No
n
NHLSD Score (mean f SD)
135 263
27.8k 10.5 26.7f9.8
.29
309 89
26.8 f9.8 28.0 & 10.8
.32
197 201
25.2k9.6 28.9 k 10.2
.0003
150 248
27.0f 10.1 27.2 f9.9
.91
83 313
26.5 f 10.4 29.2 k 8.3
The Nursing Home Life-Space Diameter A Measure of Extent and Frequency of Mobility Among Nursing Home Residents M a y E. Tinetti, MD, and Sandra F. Ginter, RN We developed the Nursing Home Life-Space Diameter (NHLSD) as a measure of the extent and frequency of mobility among skilled nursing facility (SNF) residents. lntrarater and interrater reliability was assessed in a small sample of SNF residents. The means and ranges of NHLSD scores, the characteristics associated with NHLSD score, and the association between NHLSD score and other functional characteristics were then determined among 398 residents of 12 SNFs. NHLSD scores ranged from 0, signifying bed- or chair-bound to 50, signifying leaving the facility daily. The correlation between NHLSD scores by two nurses was 0.951; the correlation between scores
at two points of time was 0.922. Mean score among the 398 subjects was 27.05. Decreased vision, presence of a neurologic disease, and arthritis were all associated with lower NHJSD score. Mobility (NHLSD) score was moderately correlated with other functional characteristics such as participation in social activities (Spearman’s correlation = +0.565). The NHLSD, which represents a simple and reliable assessment of mobility among SNF residents, could be used to assess the effect of interventions and to monitor changes among SNF residents. J Am
M
nit^.^ Finally, staff members are often available to aid in mobility if residents are not completely independent. The unique features of the nursing home need to be considered in assessing function, and specifically mobility, in this setting. Recently, we embarked on an observational study of the impact of mechanical restraint use among SNF residents. We felt that a careful assessment of activity level was essential to describing the total impact of mechanical restraint use. In the nursing home, as in the community, participation in higher-level social and physical activities can vary a great deal from individual to individual and depends on factors such as personal preference, past experience, and gender.j.4 We felt therefore, that assessment of extent and frequency of mobility would represent an optimal measure of activity level. In general, the farther, and more often, an individual moves around within and outside the facility, the more physical and/or social activities he or she is likely to engage in. Instruments are available for measuring dependence, or amount of assistance needed, in transfers, ambulation, and wheelchair m ~ b i l i t y . Other ~ , ~ instruments assess, either by simple observation or through techniques such as videotapes, the safety and effectiveness of specific componentsof balance and Measurements of extent of movement that categorize residents into “bedbound,” ”bed to chair,” or “ambulatory” groups or mild, moderate, or severe im-
aneuvering through the environment is central to functioning. Basic activities of daily living (ADLs) such as eating, dressing, bathing, and toileting all require at least some movement.’ Participation in higher-level social and physical activities obviously depends on traveling to the location of these activities. Although the dependence of functioning on mobility is true in the community as well as in nursing homes, movement within institutions has several unique features. First, the places to which residents are likely to travel, such as dining rooms, recreational areas, and nurses’ stations, are more limited and defined; all residents travel to the same location for the same activity. Second, the environment usually is adapted for frail persons by incorporating features such as non-skid floors,railings along walls, and alternatives to stairs. In addition, nursing homes, at least skilled nursing facilities (SNFs),are adapted for wheelchair mobility, a mode of personal mobility used more commonly in nursing homes than in the commu-
~
From the Department of Medicine, Yale University School of Medicine, New Haven, Connecticut. Supported in part by a grant from the Cox Foundation. Dr.Tmetti was supported in part by an N.I.A. academic award. Address correspondence and reprint requests to Mary E. Tinetti, MD, Department of Medicine, Yale University School of Medicine, P.O.Box 3333,333 Cedar Street, New Haven, CT 06510. 0 1990 by the American Geriatn’cs Society
Geriatr SOC38:1311-1315,1990
0002-8614/90/$3.50
1312 TINETTI AND GINTER
pairment, although available, may not capture the spectrum of mobility possible or may not be sensitive to clinically relevant amounts of change.lOJ1We adapted the Life-Space Diary to the nursing home setting, therefore, in order to capture the full spectrum of movement possible among SNF residents. The Life-Space Diary, based on the concept of lifespace diameter, was recently developed to measure extent and frequency of mobility in elderly persons living in the community.12 ”Life space” refers to the area throughout which an individual moves during a set period of time. The life space, in this recent report, was divided into concentric zones including the bedroom, the rest of the home, the grounds surrounding the home, the block in which the home was located, and the area beyond a traffic-bearing street. The concept of life space seemed ideal for use in the nursing home setting, which also includes readily recognizable zones. The aims of the present study were: (1)to develop an instrument to measure extent and frequency of mobility among SNF residents based on the concept of life-space diameter; (2) to test the reliability of this instrument; (3) to identify factors associated with amount of movement; (4) to correlate life-space mobility with other functional measures such as basic activities of daily living and participation in social activities; and (5) to assess the spectrum of mobility in multiple SNFs.
METHODS Based on the intended purpose and use, we determined that the mobility instrument would need to fulfill the following requirements: (1)it could be used in a large number of SNF residents residing in several different homes (i.e., instrument should be generalizable); (2) it would be sensitive to clinically relevant changes in mobility; (3) it could be used for residents whose mode of transportation was either walking or wheeling a wheelchair; (4) it correlated with other functional outcomes such as participation in social activities; and (5) it could be completed reliably by multiple observers. The last criterion was felt to be necessary because self-report is not reliable from cognitively impaired SNF residents, and residents are cared for by many staff members.
IAGS-DECEMBER 1990-VOL 38, N O . 12
TABLE 1. WORDING AND SCORING OF THE NURSING HOME LIFE-SPACE DIAMETER (Within the last 2 weeks, how often has moved around,. . . . . . ?) Diameter 1, Within his or her own room 2, Outside the room, within the unit 3, Outside the unit, throughout the facility 4, Outside the facility (i.e., left the facility) Frequency Would yousay . . . 5, > 3 times a day 4 , 1 - 3 times a day 3, > 2 times a week 2, At least weekly 1, Less than weekly 0, Never
+
NHLSD = 1 (diameter 1 X frequency 1) 2 (diameter 2 X frequency + 3 (diameter 3 X frequency 3) 4 (diameter 4 X frequency a). lndependence of movement can be incorporated into score by multiplying by 2 if movement was done without human assistance. 2)
+
Breaking frequency down further, for example, by number of trips daily, although improving sensitivity of the NHLSD, would compromise reliability. Two weeks was chosen as the time frame to reflect a reasonable period of time during which staff recall could be considered reliable and during which major changes within an individual’s habits would be infrequent. Independence, referring to whether the resident was able to maneuver alone or required human assistance, was added as an optional component. In order to ensure understanding of the concept and questions, to select optimal wording, and to ensure ease of administration a preliminary instrument was reviewed by several nurses. Based on this review, minor changes in wording were made. The final instrument, with scoring, is shown in Table 1.
First Phase: Reliability Testing The NHLSD was subjected to interrater and intrarater reliability testing. The subjects included residents at three New Haven nursing homes. A nurse research assistant randomly selected every tenth chart off the rack. Excluding subDevelopment of the Nursing Home Life-Space Di- jects who were bed- or chair-bound or restrained, she ameter A preliminary Nursing Home Life-Space Diam- reviewed charts until 25 residents, including nine males eter (NHLSD) was developed, which included compo- and 16 females, were enrolled. The average age of subnents of frequency and extent of mobility. Extent of jects was 82 years (range, 69 -93). mobility was measured by dividing the nursing home The nurse-researcher administered the NHLSD to the into the following logical zones: the resident’s room, the two nurses most involved in each subject‘s care during unit or nursing station on which the resident resides, the the day shift. Day-shift staff members were chosen berest of the facility beyond the unit, and any area outside cause this is the time during which most mobility and the facility. For ease of administration, frequency was activity occurs. The nurse-researcher returned 10 to 14 broken down to categories of more than three times a days later and readministered the instrument to one of the nurses. Correlation coefficients were determined for day, one to three times a day, more than two times a week, at least weekly, less than weekly, and never. the NHLSD scores. ~~
JAGS-DECEMBER 1990-VOL 38, NO. 12
Second Phase: NHLSD in 12Skilled Nursing Facilities The purposes of the second phase were to describe the means and ranges of the NHLSD score in different SNFs; to describe factors associated with NHLSD score; and to correlate the NHLSD score with other functional characteristics. Subjects were all residents at 12 New Haven area SNFs. Of the 1,798 residents at these 12 homes, 43 were excluded because they were less than 60 years of age; 1,041 because they had been mechanically restrained in the previous 2 weeks, thus not allowing independent mobility; and 31 6 because they were not independent with transfers. Three hundred ninetyeight subjects were included in the second phase of the NHLSD testing. The nurse-researcher extracted demographic and medical data on each subject from the SNF chart. Level of dependence in activities of daily living and participation in social activities were ascertained from the head nurse on each unit. Individual activities of daily living, including eating, dressing, bathing, and toileting were scored from 0, which indicated that the subject required total assistance, to 3, which indicated that subject was completely independent. Frequency of participation in social activities sponsored by the SNF was scored on a five-level scale from 0 (never) to 4 (daily). The NHLSD was administered to the head nurse on each SNF unit. The formula used to calculate score is shown in Table 1. Means and ranges for the NHLSD were determined for the total sample as well as for each of the 12 SNFs. After dichotomizing continuous independent variables such as age, Student's t-tests were performed. Multiple linear regression was then performed to identify the independent predictors of NHLSD score. Finally, association between NHLSD score and level of social participation and ADL functioning were determined using Spearman's correlations. RESULTS First Phase The wording and scoring of the Nursing Home Life-Space Diameter (NHLSD) are shown in Table 1. Although possible scores ranged from 0, referring to complete bedrest, to 50, referring to leaving the facility daily, no subject scored zero because bed-bound residents were excluded. If independence of movement was incorporated into the score by multiplying by two, the maximum possible score increased to 100. Unless stated otherwise, the following scores do not include the component of independence. The mean NHLSD score among the 25 subjects was 26.2 f 9.2 (mean f SD). Scores ranged from 1 to 42 without including independence and from 2 to 76 including independence. The correlationbetween the NHLSD scores of the two nurses at time 1 was .951 (Pearson's correlation). The correlation between scores at times 1 and 2 was .922. The correlations were similar when independence was incorporated into the score.
MOBILITY AMONG NURSING HOME RESIDENTS 1313
TABLE 2. NURSING HOME LIFE-SPACE DIAMETER SCORES AT 12 SKILLED NURSING FACILITIES NHLSD Score Facility
No. of Subjects
Mean f SD
1 2 3 4 5 6 7 8 9 10 11 12
86 21 23 22 18 18 73 52 13 10 37 25
23.1 f 8.9 31.3f 9.2 29.5 f 8.9 28.9 f 10.0 30.3 f 5.4 17.6 k 8.7 25.9 f 10.1 22.8f 7.5 30.2 f 11.0 33.6 f 8.5 36.7f 8.5 32.0k 8.4
Total
398
Range
5-46 11 -46
7-42 9-46 15-42 5-35 5-50 5-42 4-46 15-42 5-50 15-43
\
27.1 f 10.0
4-50
Second Phase The overall mean NHLSD for the 398 subjects included in the second phase testing was 27.1 k 10.2, with a range of 4 to 50. The range including independence was 4 to 78. The means, standard deviations, and ranges of scores for the 12 SNFs are listed in Table 2. The associations between resident characteristics and amount of mobility are shown in Table 3. Mobility was not associated with age or sex of the residents, with TABLE 3. CHARACTERISTICS OF SUBJECTS ACCORDING TO NHLSD SCORE (n = 398)
Characteristic
Age 580 years >80 years Sex Female Male Decreased vision YeS
No
n
NHLSD Score (mean f SD)
135 263
27.8k 10.5 26.7f9.8
.29
309 89
26.8 f9.8 28.0 & 10.8
.32
197 201
25.2k9.6 28.9 k 10.2
.0003
150 248
27.0f 10.1 27.2 f9.9
.91
83 313
26.5 f 10.4 29.2 k 8.3
