The results of this study suggest that, after controlling for baseline symptom severity, participants’ clinical responses to integrated treatment also varied according to their service use patterns at the time they entered the study. A principal finding of this study is that women with high levels of baseline psychotropic medication use and medical care (i.e., hospitalizations, emergency department visits, and outpatient medical visits) had lower odds of having good responses to integrated treatment than women in the low service use cluster on three dimensions—global mental health symptoms, alcohol addiction, and PTSD symptoms. These effects were evident after controlling for a range of relevant person-level characteristics, including baseline symptom severity. This suggests that the way women were using services at the time they started integrated treatment was associated with how well integrated treatment worked to improve their clinical functioning.
The women who had high levels of psychotropic medication use and medical care may not have responded well to integrated treatment for several reasons. One possible explanation could be that they continued to use medical services intensively instead of engaging sufficiently in the targeted services associated with the intervention, primarily outpatient individual and group counseling. The data on their service use over the 12 months of follow-up did not support this hypothesis, however, instead indicating reductions in average use of medical care. Specifically, women in the high psychotropic medication and medical care cluster had, on average, approximately half as many hospital days and emergency department visits in each of the four quarters of follow-up as compared to baseline, and had about 25 percent lower costs for psychotropic medication. On the other hand, their average frequency of outpatient counseling visits did not increase in the four quarters of follow-up as compared to the quarter prior to baseline, which may indicate less than optimal engagement in intervention services. (Interestingly, their aggregated frequency of counseling visits over the 12 months of follow-up was approximately 40 percent higher than among women in the other four service groups).
Another explanation for poor clinical response to integrated treatment among women with high levels of baseline medication use and medical care may lie in the reasons for their having used those treatment services intensively at the outset. Among this group of women at baseline, 100 percent had some (defined as more than zero) psychotropic medication costs, 70 percent had some costs for outpatient medical visits, 30 percent had some inpatient hospital costs, and 37 percent had some emergency department costs. While relatively few women in this cluster had any hospital costs, as a group their average hospital costs were 2.5 times higher than the rest of the women in the study sample. Intensive use of both of psychotropic medication and outpatient medical care—paired with higher GSI and PTSD severity than their counterparts in the four other service groups—may indicate that these women faced especially difficult barriers to fully engaging in and benefiting from treatment, perhaps in part related to co-morbid serious medical conditions. For instance, nearly two-thirds of women in this group reported having a serious illness or disability at baseline, and so for many of them co-occurring medical problems may have impeded their ability to achieve improvements in clinical symptoms.
Other possible explanations exist for the poor clinical response to integrated treatment among the women with high baseline psychotropic medication and medical costs that may relate to their service use patterns at the time they entered the study. It may be that women in this cluster were overmedicated, which could have complicated co-morbid medical problems or substance abuse behavior and inhibited learning in treatment and recovery from co-occurring disorders and trauma. Another possibility is that women in this cluster may have tended to somatize their problems, lessening their likelihood to respond well to behavioral health interventions.
There are important limitations and strengths of this study. First, the integrated treatment intervention was not a standardized set of prescribed services in terms of type, frequency, or duration of use, which means the intervention experience was not uniform among participants. While all of the women in the present analysis were assigned to integrated treatment, some may have used intervention services intensively during the year of follow-up, while others may have used none at all. The quasi-experimental design of WCDVS also provided an important opportunity in this analysis to identify how women's service use patterns affected their response to the intervention. A shortcoming of cluster analysis is that the groupings of a particular study sample may not generalize to other samples/populations. This limitation was partly mitigated by having a large starting study population to categorize into like subgroups, which increased the precision and reliability of the clustering process.
Cutpoints to indicate whether participants demonstrated good clinical responses to the intervention are ultimately arbitrary and so must be interpreted with some caution. As a sensitivity analysis, we generated a second set of estimates of treatment response in symptom scores for ASI-A, ASI-D, and PTSD in the same way we did for the GSI mental health measure, where a good treatment response was operationalized as a 20 percent or greater improvement between baseline and 12 months. None of the cluster coefficients were statistically significant in either of the 20-percent-improvement models for the two ASI outcomes; however the Wald test for the ASI-D model indicated that there were generally differences across service clusters (X2=10.90, df=4, p=0.03). These results for the drug outcome were consistent with study models. The results for the alcohol model did not detect a unique effect for the women with high psychotropic medication and medical care costs as in the study model, which was likely due to insufficient variation in the distribution of alcohol outcomes in the 20-percent response model. The 20-percent model for PSS produced an effect consistent with the reported model, such that the women with high baseline psychotropic medication and medical costs had lower odds of a good clinical improvement. While cutpoints are a coarse approach to capturing meaningful clinical change, these sensitivity results were largely consistent with our study results, indicating that there were robust differences in treatment effects across service clusters. Furthermore, the poor response to integrated treatment among women with high levels of psychotropic medication and medical care on three of the four symptom domains also suggests that a strong pattern of treatment effect exists for this sub-group of women.
Two other caveats regarding effect measurement are important to consider. Given that these study analyses were exploratory in nature, it is possible that applying the .05 level of significance may have captured some spurious results in treatment effect across groups. Although a more stringent threshold for statistical significance in future research may be prudent, the findings presented here are compelling nonetheless given the patterns of effect found for women with high psychotropic medication and medical care costs on three of the four symptom domains. Also, it is possible that interaction effects between clusters and covariates may have been present in this study sample that were not measured due to relatively small sample sizes in baseline and outcomes conditions across the service clusters.
These study results have important implications for programs providing integrated treatment to women with co-occurring disorders and histories of abuse victimization. Careful assessments of treatment needs and engagement in targeted services should be conducted for women in integrated treatment programs who have used especially high levels of psychotropic medication and medical care, as it may be that high use of medical care is due to insufficient or non-use of mental health services. Special efforts may be required to address circumstances surrounding their high-intensity use of medical care, ranging from co-morbid medical conditions, to untreated mental health, substance abuse and trauma, to current victimization, that may keep them from fully engaging in treatment and achieving improvements in their mental health and posttraumatic stress symptoms. Further, women who were low-intensity service users appeared to respond well to integrated treatment in comparison, and so identifying the women in this population who may be underutilizing treatment services and targeting integrated treatment to them could improve its cost-effectiveness.
Integrated treatment for women with co-occurring disorders and histories of abuse has been demonstrated to significantly improve their clinical outcomes above and beyond usual care. In addition to these important population-level outcomes, this study provides new evidence that integrated treatment may work differently depending on participants’ prior service use patterns. This information can be used to target integrated treatment interventions to women who are likely to respond positively and achieve meaningful improvements in their functioning.