The cost-effectiveness of independent housing for the chronically mentally ill: do housing and neighborhood features matter?

Health Services Research, Oct, 2004 by Joseph Harkness, Sandra J. Newman, David Salkever

Building Features

The results support the hypothesis that better quality buildings convey mental health benefits. Buildings in need of repair were associated with a 58 percent increase in residential instability (p = .01) and a 28 percent increase in CMTY costs (p = .06). Older properties, which, all else equal, are likely to be in worse condition, were also associated with worse outcomes; every additional 10 years of a property's age raised the probability of a mental health hospitalization by 16 percent (p = .05) and increased residential instability by 13 percent (p = .01). Finally, each additional amenity feature was associated with an 11 percent reduction in CMTY costs (p = .06). There is also evidence that individuals with CMI fare better in smaller-scale residential settings, as expected, with each additional apartment in a multi-unit dwelling increasing residential instability by 10 percent (p<.01).

The effects of the presence of other tenants with CMI in the building were mixed but tending toward the beneficial. On one hand, every 10 percentage point increase in the proportion of tenants with CMI decreased residential instability by 5.5 percent (p = .02), which indicates favorable effects. On the other hand, a higher proportion of tenants with CMI was weakly associated with higher CMTY costs (p = .14) and a higher probability of a mental health hospitalization (p =. 13).

These results do not necessarily conflict. For example, buildings with a higher proportion of tenants with CMI may be more frequently visited by case managers, who may share information about their participants with each other, potentially resulting in a more rapid response to developing psychiatric problems. More prompt delivery of services could contribute to higher costs, but could also reduce residential instability.

Neighborhood Features

In contrast to past research, the results offer only weak support for the hypothesis that individuals with mental illness fare better in diverse-disorganized neighborhoods. Although each nonresidential land use on a block is associated with a 15 percent reduction in CMTY costs (p = .02), the point estimates for the effects of nonresidential land uses on the likelihood of mental health hospitalization, and costs if hospitalized, are not statistically significant (p-values around .20), though they are negative. The point estimates on the effects of homeownership are all positive, consistent with the hypothesis, but, again, none are statistically significant. The neighborhood poverty rate has no effect on any outcome.

The quadratic of percent white population suggests that the mental health hospitalization rate is lowest for individuals living in racially mixed neighborhoods, but the opposite holds for costs if hospitalized. When the two parts are combined, the second part (costs if hospitalized) dominates, which undermines the diverse-disorganized neighborhood hypothesis. The validity of this result is questionable, however, because further examination shows that the link between living in a mixed-race neighborhood and hospitalization costs held for white men, but not blacks or women. This is problematic not only because there is no strong theoretical reason to expect white men, in particular, to be affected by the racial composition of their neighborhoods, but also because there were relatively few white participants that lived in mixed or predominantly black neighborhoods: three-fourths of whites lived in neighborhoods where at least 76 of the population was also white. The relative rarity of cases raises the possibility these results may be a statistical anomaly.