Updated Analyses of Trends in Use of Assistive Devices. Analysis of Independent Device Use, Hours of Care, and Unmet Need

01/07/2013

This new analysis takes a first multivariate look at factors associated with independent device use for some activities and the association of independent device use with hours of care and unmet need in cross-section. To abstract from the larger question of whether any devices are used and focus on the effect of independent use on care hours and unmet need, the analysis sample is limited to community-residing elders with disabilities using both help and devices.

Methodology

Separate models are used to examine the probability that an individual accommodating disabilities with any combination of help and device use manages at least one activity with only assistive devices, and the association between independent device use and hours of care received and unmet need reported. Models examine total hours of care, informal care hours, formal care hours, and unmet need for all persons using help and devices and for the subset managing at least one activity with devices only. The central explanatory variable is the number of activities for which devices alone are used, although interesting findings for the presence and need for home accommodative features also are discussed briefly. Other explanatory variables include physical limitations, number of disabilities, number of disabilities for which devices are used, health conditions, and basic demographic and economic characteristics. Probit regression is used estimate the probability of any independent device use and reports of unmet need and linear regression to estimate care hours.

Descriptive Results

Table 4 provides means and proportions of characteristics used in the multivariate models for elders using both help and assistive devices by whether any activities are performed with devices alone. Differences in the last column reflect how those performing no activities with devices only differ from those performing at least one activity with devices alone.

  TABLE 4. Characteristics of Community-Residing Elders Using Both Help and Devices for IADLs and ADLs by Whether Any Activity is Performed with Devices Only, 2004  
  Mean/Proportion   Difference  
  None     Any  
Physical limitations
   None or upper body onlya 5.2 5.7 -0.5
   Lower body only 18.1 31.9 -13.9**
   Both upper and lower body 76.8 62.3 14.4**
Cognitive impaired 40.9 18.0 22.9**
Total # of limitations (0-14) 8.9 5.6 3.3**
# of ADLs with equipment (0-6) 2.4 2.5 -0.1*
# of ADLs with equipment only (0-6) --- 1.9 ---
   Any ADL with help/equipment most of the time   83.0 89.4 -6.4**
   Any home accommodative features present 64.0 73.2 -9.1**
   Any home accommodative features desirable 51.2 44.0 7.2**
Duration of chronic disability
   Less than 1 yeara 11.2 9.7 1.4
   1 year to 5 years 49.8 49.5 0.3
   5 years or longer 39.0 40.8 -1.8
Age
   65 - 74a 31.1 23.7 7.4**
   75 - 84 39.5 40.2 -0.7
   85 - 94 23.5 30.8 -7.3**
   95+ 5.9 5.3 0.6
Female 64.5 74.7 -10.2**
Living arrangement
   Lives with spouse 22.1 45.0 -23.0**
   Lives with others 45.2 30.1 15.0**
   Lives alonea 32.8 24.8 8.0**
Residential type
   Private residence 84.8 73.3 11.5**
   Community residential care 9.3 15.2 -5.9**
   Other setting for older or disabled persons 5.9 11.5 -5.6**
Number of nonresident daughters nearby 0.7 0.7 0.0
Education
   Less than high schoola 47.8 40.0 7.9**
   High school 24.6 29.3 -4.7*
   Some college 27.5 30.7 -3.2
Medicaid eligible 28.7 23.6 5.1**
Annual Income
   <$10,000# 26.3 25.1 1.2
   $10,000 - <$20,000 33.6 37.9 -4.3*
   $20,000 - <$30,000 19.4 18.4 0.9
   $30,000 - <$40,000 9.9 9.2 0.7
   $40,000 or more 10.8 9.3 1.5
Race/ethnicity
   Black 10.5 8.2 2.3
   NonBlacka 89.5 91.8 -2.3
   Hispanic 7.3 5.6 1.7
Health conditions/events
   Disabetes 29.1 28.3 0.8
   Heart attack/other heart problem in the last 12 months 29.0 28.4 0.6
   Paralysis/other nervous system disorder 20.0 12.4 7.6**
   Asthma/bronchitis in the last 12 months 26.6 22.5 4.1
   Pneumonia in the last 12 months 10.4 8.8 1.6
   Broken hip or other bone in last 12 months 11.7 10.0 1.7
   Stroke in the last 12 months 14.7 8.1 6.6**
Recent utilization events
   Hospitalization in last 6 months 19.7 17.3 2.4
   Home health use in last 6 months 23.6 18.5 5.1**
   SNF use in last 6 months 6.2 6.3 -0.1
   Hospice use in last 6 months 3.3 0.6 2.7**
Proxy respondent 67.5 34.5 33.0**
Survive less than 1 year 17.1 10.0 7.0**
Region
   Northeast 18.6 20.0 -1.4
   Midwesta 21.6 24.5 -3.0
   South 40.0 35.3 4.8*
   West 19.8 20.2 -0.4
  1. Omitted category.

**(*) difference significantly different from zero at the 5%(10%) level in a two-tailed test.

Those performing no activities with devices only have higher levels of physical and cognitive impairment, although they are generally similar with respect to health conditions and events examined. They have a greater level of disability as measured by the proportion with both upper and lower body limitations, their rate of cognitive impairment, and their larger average number of ADL and IADL disabilities. Both groups use devices for an average 2.5 ADLs, but despite their higher disability level, those performing no activities independently with devices are less likely to report needing help or using devices most of the time. They are also less likely to have accommodative features in the home and more likely to identify accommodative features that would "make things easier or more comfortable."

Those with no independent device use also are more likely to be under age 75 and less likely to be age 85 or older, although the two groups are about equally likely to be age 95 or older. They also are less likely to be female. As for potential informal support resources, they are less likely to be living with a spouse and more likely to be living with others or alone, although there is no difference in the average number of nonresident daughters living nearby. They are more likely to be living in a traditional private residence and less likely to be in either residential care or other settings for older persons or those with disabilities. They are more likely to have less than a high school education and to be enrolled in Medicaid, but there are inconsequential differences in the income and race/ethnicity distribution within the two groups.

The only significant differences in the health conditions examined are their higher likelihood of having paralysis or a nervous system disorder and having had a stroke within the previous year. They are more likely to have had Medicare home health or hospice care within the previous 6 months. They also are nearly twice as likely to have a proxy respondent and significantly more likely to be in their last year of life, two measures included to capture the potential for unmeasured differences in illness or frailty. Their distribution across geographic regions is similar to that for persons managing at least one activity with only assistive devices.

  TABLE 5. Mean Hours of Care and Proportion Reporting Unmet Need for help among Community-Residing Elders Using Both Help and Devices for IADLs or ADLs by Whether Any Activity is Performed with Devices Only, 2004   
  Activities with Devices but No Help
None Any   Difference  
Mean or
  Proportion  
Mean or
  S.E.  
Mean or
  Proportion  
Mean or
  S.E.  
Total hours of care 55 1.81 23 1.19 32**
   Informal hours 41 1.65 17 1.12 24**
   Formal hours 14 1.16 6 0.56 8**
Unmet need
   Any unmet need for help 67.4 1.8 60.7 1.67 6.7**
   Need help/more help with ADLs   24.3 1.9 19.2 1.64 5.1**
   Need help with IADLs 68.8 3.2 68.0 3.01 0.8
**(*) difference significantly different from zero at the 5%(10%) level in a two-tailed test.

Means and proportions of hours of care and unmet need are provided in Table 5. Those who perform no activities with only devices clearly receive significantly more hours per week of both informal care (24 hours) and formal care (8 hours). They also are more likely to report unmet need for help with any activity, and with additional ADLs or more help with ADLs for which they already are receiving help, but equally likely to report unmet need for help with IADLs.

Multivariate Results

Results presented and discussed in this section focus on identifying explanatory variables significantly related to the probability of managing any activity with devices alone, and on the association of independent device use with hours of care received in the last week and reports of unmet need in cross-section. Therefore, they cannot be interpreted as reflecting causal relationships. Full regression results are provided in the appendix.

  TABLE 6. Probability of Any Independent Use of Devices among Community-Residing Elders Receiving Assistance and Using Devices for IADLs or ADLs, 2004  
    Marginal Effect  
Total # of limitations (0-14) -0.09**
# of ADLs with equipment (0-6) 0.15**
Any ADL with help/equipment most of the time   0.20**
Any home accommodative features present 0.08*
Age
   75 - 84 0.10**
   85 - 94 0.17**
   95+ 0.16**
Living arrangement
   Lives with spouse -0.20**
   Lives with others -0.10**
Recent utilization events
   Hospice use in last 6 months -0.22*
Proxy respondent -0.11**
NOTE: **(*) marginal effect significantly different from zero at the 5%(10%) level in a two-tailed test. Full regression results provided in Appendix Table A1.

Factors Associated with Independent Device Use

Only a handful of factors included in the models are significantly related to the probability that an elder uses assistive devices independently for at least one activity (Table 6). Not surprisingly, the likelihood of independent device use falls as the total number of limitations increases and rises as the total number of devices used for ADLs (with or without help) rises. The frequency with which accommodation is needed also is associated with a higher likelihood of independent use, as is the presence of accommodative features in the home. The presence of accommodate features, like living arrangements more generally, is likely to be jointly determined with other accommodations including device use, and so is not truly independent. Perhaps counterintuitively, being age 75 or older and even age 95 or older was associated with a higher likelihood of independent device use. This result may suggest unmeasured severity of illness or limitation among those with earlier onset disabilities. Living with either a spouse or others is associated with a lower likelihood of independent device use. This finding may be consistent with the argument sometimes advanced that the likelihood and amount of help received for any level of need is affected by the availability of potential caregivers, and that help, once received, may persist even during periods when need is less. Being a hospice patient and having a proxy respondent both are associated with a lower likelihood of independent device use, which, again, may reflect that these factors indicate otherwise unmeasured severity of illness or frailty. Being in the last year of life itself was not significantly related to use of devices independently.

Association of Independent Device Use with Hours of Care and Unmet Need

Independent use of devices is strongly associated with reduced hours of care both in the full sample using help and devices and in the subset managing one or more activities with only devices (Table 7), but is not associated with increased reports of unmet need for help. Each activity performed independently with devices is associated with six fewer hours of care per week for the full sample and nearly five fewer hours among those using only devices for at least one activity. For the full sample each activity performed independently with devices is associated with three fewer informal hours per week. Although the magnitude is only slightly smaller for those using devices only for at least one activity, the difference is not statistically significant. In both samples each activity performed solely with devices is associated with significantly lower formal care hours.

TABLE 7. Effect of Independent Device Use on Hours of Care and Reports of Unmet Need for Help for Community-Residing Elders Receiving Assistance and Using Devices for IADLs or ADLs, 2004
Outcomes All Elders Using  Help and Equipment Elders Using Devices Only for  at Least One Activity
Coefficient of
  Marginal Effect  
  P-Value   Coefficient of
  Marginal Effect  
  P-Value  
Total hours of carea -6.12 0.000** -4.92 0.021**
   Informal hours -3.15 0.002** -2.70 0.158
   Formal hours -2.98 0.000** -2.21 0.030**
Any unmet need for helpb -0.05 0.000** -0.02 0.334
   Unmet need for help/more help with ADLs   -0.04 0.001** -0.06 0.004**
   Unmet need for help with IADLs -0.04 0.002** 0.03 0.198
NOTES: **(*) coefficient is significantly different from zero at the 5%(10%) level in a two-tailed test.
  1. Coefficient estimate from linear regression. Full regression results are provided in Appendix Table A2 for all elders using help and equipment, and Appendix Table A3 for elders using devices only for at least one activity.
  2. Marginal effect from Probit estimation. Full regression results are provided in Appendix Table A4 for all using help and equipment, Appendix Table A5 for elders using devices only for at least one activity.

Although the magnitude is small, each activity managed with devices alone is associated with significantly lower rates of unmet need for both ADLs and IADLs in the full sample and a significantly lower rate of unmet need for ADLs within the subset using devices only for at least one activity. This result supports a tentative conclusion that lower hours of care associated with independent device use are not associated with higher unmet need for care.

All equations were run with and without indicators of home accommodative features present or considered desirable, which may be considered as a complement to device use. Inclusion has essentially no effect on sign, magnitude, or significance of independent device use, but reveals interesting findings with respect to the association of accommodative features with outcomes (see Appendix Tables A2-A5). Presence of home accommodations is associated with greater hours of formal care, while perceived desirability of features not present in the home was associated with about three additional hours of informal care and nearly 3 hours less formal care in the previous week. A similar pattern was evident within the subset using devices independently, with equivalent but offsetting effects on hours of formal and informal care, although the positive effect for informal care hours was not significant.

On the other hand, accommodative features present were not associated with unmet need, but identification of desirable features not present was positively and significantly associated with unmet need for both ADL and IADL help for the full sample using help and devices. Again, results were similar for the subset using devices alone for at least one activity. But, although the negative associations of accommodative features with lower unmet need overall and unmet for ADL help were statistically significant, the association for unmet need for IADL help, although positive and of similar magnitude to that for the full sample, was not significant in the smaller sample.

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