A 60-week prospective randomized controlled trial of Targeted Training in Illness Management vs. treatment as usual in individuals with serious mental illness and diabetes mellitus

Abstract

Objectives

Targeted Training in Illness Management (TTIM) addresses serious mental illness and diabetes (DM) concurrently and is designed to improve psychiatric symptoms, functioning, general health and DM control. This 60-week, randomized controlled trial assessed TTIM vs. treatment as usual in 200 individuals with serious mental illness and diabetes.

Methods

Clinical Global Impression (CGI), Montgomery Asberg Depression Rating Scale (MADRS) and Brief Psychiatric Rating Scale (BPRS) assessed symptoms. Global Assessment of Functioning (GAF) and Sheehan Disability Scale (SDS) assessed functioning. Short-form 36 (SF-36) assessed general health and serum glycosylated hemoglobin (HbA1c) assessed DM.

Results

Average age was 52.7±9.5 years, 54% African-American. Psychiatric diagnoses were depression (48%), schizophrenia (25%) and bipolar disorder (28%). Baseline depressive severity was substantial while psychosis severity was modest. There was greater improvement at 60-weeks in TTIM for CGI (p=<.001) and MADRS (p=.016) and no difference on BPRS. There was greater TTIM improvement on GAF (p=.003) and an improvement trend on SDS (p=.086). There were no group differences on SF-36 or HbA1c means. Diabetes knowledge was significantly improved for TTIM vs. treatment as usual. In post-hoc analyses among individuals within recommended American Diabetes Association HbA1c targets adjusted for high comorbidity at baseline (53%), TTIM had minimal HbA1c 60-week change, while treatment as usual worsened.

Conclusions

TTIM was associated with improved psychiatric symptoms, functioning, and DM knowledge compared to treatment as usual. General health and DM did not significantly differ when analyzing the whole group, although there were post-hoc analysis differences among sub-groups based upon DM control at baseline.

Introduction

Individuals with serious mental illness such as schizophrenia, bipolar disorder, and recurrent depression die earlier than individuals in the general population, losing on average, 9-32 years of life^1-4. Much of the premature mortality among people with serious mental illness is due to medical comorbidities such as diabetes mellitus (DM). Type 2 DM is common among those with serious mental illness, and worsened by inactivity and poor diet as well as treatment with second-generation antipsychotics^5-9.

Active self-management is crucial in minimizing the morbidity and mortality associated with chronic mental disorders and chronic medical conditions^10-13. There are few practical treatment models^10-16 and a recent literature review found that the strength of evidence was low for most interventions¹³.Targeted Training in Illness Management (TTIM) is a novel self-management approach which targets serious mental illness and comorbid DM concurrently. TTIM focuses on enhancing care engagement, including the use of peer educators to facilitate communication and model behavioral changes. Preliminary work suggests that TTIM is highly acceptable to patients, and may improve both outcomes when added onto usual care¹⁷.

This randomized controlled trial (RCT) assessed effects of TTIM vs. treatment as usual in 200 individuals with serious mental illness and diabetes. The primary aim was to test whether an intervention that targets serious mental illness and-diabetes comorbidity and is designed to be practical in a primary care system will improve serious mental illness symptoms, functional status, general health status and DM-specific outcomes.

Methods overview

This project was a prospective, 60 week, RCT testing TTIM vs treatment as usual in 200 individuals with serious mental illness and diabetes. Individuals were randomized using a computer-generated list, allocation concealment, a 1:1 allocation ratio and block randomization using block sizes of 4-8 consecutive patients. Primary outcomes were psychiatric symptom severity, functioning, general health, and DM control. Research assessments were conducted at baseline (prior to randomization), and at 13, 30 and 60 weeks.

Study Participants

Inclusion criteria included having schizophrenia, schizoaffective disorder, bipolar disorder or major depressive disorder confirmed by the Mini-International Neuropsychiatric Interview (MINI)¹⁸; having Type 2 DM; being age ≥18;able to communicate in English; and able to provide written, informed consent. Exclusion criteria included active suicidality or homicidality, inability to participate in study procedures, pregnancy, or dementia. The study was approved by the local institutional review board (IRB). The investigators have previously published details on recruitment and retention methods¹⁹. In addition to clinician and self-referrals, individuals were identified from the health system’s electronic health record, either by having serious mental illness on their problem list or being treated with medication for serious mental illness (lithium, mood stabilizer, antipsychotic). Using an IRB approved process, these individuals were consecutively contacted and invited to participate in the study.

TTIM Intervention

TTIM is a group-based psychosocial treatment that blends psychoeducation, problem-identification, goal-setting, behavioral modeling, and care linkage designed for individuals with serious mental illness and DM. TTIM is derived from the Life Goals Program (LGP), by Bauer and colleagues.^20,21 and the Diabetes Awareness and Rehabilitation Training (DART) by McKibbin and colleagues¹². While LGP focused mainly on mental health outcomes and DART focused on DM outcomes, TTIM combines these foci and enhances social support using peer educators.

TTIM is delivered in a 2-step process described in detail elsewhere ^22,23. In step one (See on-line material),12 weekly, group-format, in-person sessions (6-10 participants per group) are co-delivered by a nurse educator and a peer educator with serious mental illness and DM^{22, 23}. In step 2, over the 48-weeks following the group sessions, participants have brief (10-15 min) telephone maintenance sessions with peer educators and nurse educators. Telephone sessions occur every other week for the first 3 months, and monthly thereafter.

Treatment as usual

Patients with DM in this safety-net health system visit their primary care practitioner on average 4-6 times per year. The site characteristics and standard care is described in on-line appendix materials. Most (79%) of the sample received medical care within the system, while 46% received mental health care within the system.

Intervention evaluation

TTIM session attendance was assessed at each session. Acceptability was assessed upon completion of the group-session series with a brief, self-rated questionnaire. Fidelity to TTIM processes, content, and format was evaluated by non-interventionist study staff randomly attending 20% of TTIM sessions using a standardized checklist.

Measures

Table 1 illustrates baseline demographic and clinical variables which included health literacy screening²⁴. The self-reported Charlson Index evaluated medical comorbidity²⁵. Primary outcomes evaluated 4 key domains: mental illness symptom severity, functioning, general health and DM control. Additional physical health outcomes included body mass index (BMI) and blood pressure.

Table 1.

Baseline clinical characteristics of individuals with serious mental illness and DM participating in targeted training in illness management (TTIM) vs. treatment as usual

Variable	All individuals N= 200		TTIM N= 100		Treatment As Usual N= 100		SAMD**
	N	%	N	%	N	%
Age (mean, SD)	52.7±9.5	-	52.8±9.7	-	52.6±9.7	-	.021
Gender Female (N, %)	128	64%	63	63%	65	65%	.050
Race (N, %)
Caucasian	74	37%	38	38%	36	36%	.001
African-American	107	54%	52	52%	55	55%	.001
Other	19	10%	10	10%	9	9%	.010
Hispanic (N, %)	17	9%	10	10%	7	7%	.030
Education (mean years, SD)	12.6±2.7	-	12.7±2.5	-	12.5±2.9	-	.074
Health Insurance (N, %)
Private	7	4%	5	5%	2	2%	.026
Medicare	69	35%	35	35%	34	34%	.001
Medicaid	95	48%	48	48%	47	47%	.002
Other/none	29	15%	12	12%	17	17%	.015
Serious Mental Illness Diagnosis
Schizophrenia	49	25%	29	29%	20	20%	.009
Bipolar Disorder	56	28%	22	22%	34	34%	.009
Major Depressive Disorder	95	48%	49	49%	46	46%	.001
Serious mental illness duration (mean years, SD)	18.5±12.6	-	19.1±12.9	-	17.8±12.4	-	.103
DM duration (mean years, SD)	10.1±7.8	-	9.8±7.5	-	10.3±8.1	-	.064
AHA-defined HTN (N, %)	87	44%	45	45%	42	42%	.001
On second generation antipsychotic medication (N, %)	73	37%	40	55%	33	45%	.069
Insulin user (N, %)	88	45%	43	44%	45	46%	.001
Charlson Index (mean, SD)	2.2±1.6	-	2.4±1.7	-	2.1±1.5	-	.137
BHLS (mean, SD)	12.5±3.2	-	12.5±3.0	-	12.4±3.3	-	.022
CGI (mean, SD)	4.3±0.9	-	4.3±1.0	-	4.3±0.9	-	<.001
MADRS (mean, SD)	24.1±9.1	-	23.1±9.4	-	25.0±8.8	-	.209
BPRS (mean, SD)	40.0±9.3	-	38.7±9.8	-	41.3±8.9	-	.278
GAF (mean, SD)	51.6±11.5	-	51.8±11.0	-	51.4±11.9	-	.035
Sheehan Disability (mean, SD)	17.9±6.2	-	18.0±5.8	-	17.8±6.5	-	.033
SF-36 (mean, SD)
Physical	39.6±10.5	-	39.4±10.1	-	39.8±10.9	-	.038
Mental	36.4±11.4	-	37.2±10.6	-	35.6±12.1	-	.141
HbA1c (mean, SD)	8.2±2.3	-	8.2±2.0	-	8.0±2.4	-	.091
Systolic BP (mean, SD)	134.8±21.2	-	135.0±20.7	-	134.5±21.7	-	.024
BMI (mean, SD)	36.0±8.7	-	35.4±8.0	-	36.6±9.4	-	.138

DM= Diabetes mellitus, AHA = American Heart Association, HTN= hypertension, Charlson Index= Charlson comorbidity index (Possible scores range from 0 to 9, with higher scores indicating higher comorbidity), BHLS= Basic Health Literacy Screen CGI = Clinical Global Impression (Possible scores range from 0 to 7; higher scores = greater psychopathology), MADRS = Montgomery Asberg Depression Rating Scale (range 0 to 60; higher scores = greater depression severity), BPRS= Brief Psychiatry Rating Scale (range 7 to 126; higher scores = greater symptom severity), GAF= Global Assessment of Functioning (range 1 to 100; higher scores = better functioning), Sheehan Disability= Sheehan Disability Scale (range 0 to 30; higher scores = greater disability), SF-36 = Short-form 36 (general health status)(Norm-based scores are placed on the same metric with a mean of 50 and standard deviation of 10. Scores above 50 reflect higher functional health status than the general population average and scores below 50 reflect lower functional health status than the general population), HbA1c= glycosylated hemoglobin, BMI= Body Mass Index.

^**SAMD= standardize absolute mean difference. Source: David B Wilson, George Mason University. http://www.campbellcollaboration.org/escalc/html/EffectSizeCalculator-SMD1.php [online effect size calculator]

Serious Mental Illness Symptoms

The Clinical Global Impression (CGI) is a broad measure of global psychopathology that evaluates illness severity on a 1 to 7 point continuum²⁶. Possible scores range from 0 to 7, with higher scores indicating greater psychopathology.

Montgomery Asberg Depression Rating Scale (MADRS)

The MADRS is a 10-item depression severity scale widely utilized in studies with patients with serious mental illness²⁷. Possible scores range from 0 to 60 with higher scores indicating worse depression.

Brief Psychiatric Rating Scale (BPRS)

The BPRS²⁸ measures psychotic and non-psychotic symptoms in serious mental illness. Possible scores range from 7 to 126, with higher scores indicating greater symptom severity.

Functional Status

Global Assessment of Functioning (GAF)

The GAF is a 100-point single-item scale that measures global functioning ²⁹. Possible scores range from 1 to 100, with higher scores indicating better functioning.

Sheehan Disability Scale (SDS)

The SDS measures role impairment in three domains (work/school; family life/home; social life)³⁰. Possible scores range from 0 to 30, with higher scores indicating greater disability.

General Health Status

The Short Form 36 Health Survey (SF-36) is a self-report of general health³¹ divided into a physical component summary (PCS) and mental component summary (MCS). Norm-based scores are placed on the same metric with a mean of 50 and standard deviation of 10. Scores above 50 reflect higher functional status than the average population and scores below 50 reflect lower than average function.

DM control

DM control was evaluated with serum glycosylated hemoglobin (HbA1c) drawn at study baseline, 30 and 60 weeks. This indicates relative DM control over the past 3 months with scores ideally< 7.

Secondary Outcomes Directly Related to Diabetes Control

TTIM is designed to impact behaviors known to be key for DM control. This includes increasing DM knowledge and self-care activities such as diet, exercise, and self-monitoring of glucose. Diabetes knowledge was assessed with the Brief Diabetes Knowledge Test ^12,32. Higher scores indicate greater DM knowledge. DM self-care was measured with the Diabetes Self-Care Activities Questionnaire (DSCA), a brief self-report of DM self-management that includes general diet, DM-specific diet, exercise, glucose testing, foot care, and smoking³³.

Data Analysis

Analyses were conducted in SAS software version 9.3, SPSS version 23, and R software version for 64-bit Windows operating system. The level of significance except where noted otherwise was α = .05. Descriptive baseline statistics are shown in Table 1. Table 2 shows raw unadjusted means and standard deviations for outcomes at baseline, 13, 30, and 60-weeks. The groups were compared according to original assignment, regardless of intervention participation (intent to treat).Table 2 p-values correspond to the group-by-time interaction effect using linear mixed effects analyses. These series of mixed effects models (separate for each outcome in Table 2) also included main effects for group and time along with a random intercept. A mixed effects approach is well-suited for handling missing data by a maximum likelihood algorithm under the assumption that the missingness is dependent on the data at hand (“missing at random (MAR)”) assumption³⁴. Bonferroni corrections were conducted to adjust for multiple comparisons within each of the 4 main outcome domains (serious mental illness symptoms, functioning, general health status, DM control). Given the broad inclusion criteria in relation to DM status, post hoc analyses of change in HbA1c among subgroups were considered. Baseline HbA1c as per American Diabetes Association (ADA) thresholds, which recommend adjustment for individuals with comorbidities was used to demarcate groups. Wilcoxon rank-sum tests were conducted to compare differences in change over 30- and 60-week periods between the two arms.

Table 2.

Change in primary outcomes from baseline at 13, 30 and 60 week outcomes

Variable *	Baseline		13-weeks		30 weeks		60 weeks		Statistic p-value**
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Mental Illness Symptoms
CGI
TTIM	4.27	1.0	4.27	1.0	3.70	1.1	3.24	1.1	<.001†
Treatment As Usual	4.28	.9	4.28	.9	4.14	1.0	4.03	1.1
MADRS
TTIM	23.05	9.4	15.41	8.9	17.33	9.6	15.92	10.0	.016†
Treatment As Usual	25.05	8.8	21.18	10.00	20.90	10.3	18.55	8.8
BPRS
TTIM	38.71	9.8	32.08	9.1	33.16	7.8	32.04	9.0	.785
Treatment As Usual	41.30	8.9	36.76	8.3	36.04	8.8	35.89	8.7
Functioning
GAF
TTIM	51.79	11.0	59.56	12.4	60.19	13.1	61.05	13.1	.003†
Treatment As Usual	51.44	11.9	53.20	12.5	53.31	13.6	53.29	13.3
SDS
TTIM	17.98	5.8	14.10	6.8	15.20	7.4	15.0	7.4	.086
Treatment As Usual	17.75	6.5	17.36	6.8	16.94	7.1	16.47	7.1
General Health Status
SF-36 – Mental Health Component
TTIM	37.17	10.6	n/a		40.59	11.9	42.05	11.1	.872
Treatment As Usual	35.62	12.1	n/a		39.99	12.5	39.58	11.4
SF-36 - Physical Health Component
TTIM	39.38	10.1	n/a		39.84	11.0	39.65	11.1	.680
Treatment As Usual	39.76	10.9	n/a		40.37	10.5	40.81	9.3
Diabetes Control
HbA1c
TTIM	8.00	2.2	n/a		7.81	2.3	7.69	1.9	.662
Treatment As Usual	8.00	2.4	n/a		7.84	2.0	7.77	2.0
Other Physical Markers
Systolic blood pressure
TTIM	134.99	20.7	n/a		132.05	18.3	134.12	20.7	.633
Treatment As Usual	134.53	21.7	n/a		135.19	25.3	132.71	23.8
BMI
TTIM	35.44	8.0	n/a		36.15	8.5	36.46	8.6	.175
Treatment As Usual	36.59	9.4	n/a		36.91	9.7	37.07	9.8

CGI = Clinical Global Impression (Possible scores range from 0 to 7; higher scores = greater psychopathology), MADRS = Montgomery Asberg Depression Rating Scale (range 0 to 60; higher scores = greater depression severity), BPRS= Brief Psychiatric Rating Scale (range 7 to 126; higher scores = greater symptom severity), GAF= Global Assessment of Functioning (range 1 to 100; higher scores = better functioning), Sheehan Disability= Sheehan Disability Scale (range 0 to 30; higher scores = greater disability), SF-36 = Short-form 36 (general health status)(Norm-based scores are placed on the same metric with a mean of 50 and standard deviation of 10. Scores above 50 reflect higher functional health status than the general population average and scores below 50 reflect lower functional health status than the general population), HbA1c= glycosylated hemoglobin, BMI= Body Mass Index.

Values are unadjusted means

^**p-value refers to the group by time interaction using linear mixed effects analyses.

^†p < .05 after Bonferroni correction within outcome domain (mental illness symptoms, functioning, general health, DM)

Results

Study flow and assignment

Figure 1 (see online appendix) illustrates study flow, with 358 individuals screened for eligibility. There were 200 individuals randomized with 100 allocated to each study arm. Of individuals allocated to TTIM, a total of 16 individuals (16%) never participated in a single TTIM session. Mean group session attendance was 7.2 (4.6) and there were 65 (66.3%) TTIM participants who completed ≥ 6 sessions. The study was conducted between December 2011 and June 2015.

Figure 1.

Flow of study screening, enrollment, randomization assignment, retention and completion

Overall sample description

Table 1 illustrates baseline sample characteristics. There were no clinically important differences between TTIM and treatment as usual as assessed by standardized absolute mean differences. Individuals had substantial baseline depressive symptoms and low levels of psychosis as reflected in mean baseline scores on MADRS and BPRS respectively. Functional status was low, with mean GAF score just over 50.

Use of psychotropic medication was extensive, with 82 (41%) on first or second-generation antipsychotic drugs, 58 (29%) on mood stabilizing drugs, and 134 (67%) on antidepressants. Among individuals with schizophrenia, 26 (53%) were on second-generation antipsychotic drugs, while 25 (45%) of individuals with bipolar disorder and 22 (23%) of individuals with depression were on second-generation antipsychotic drugs.

Safety and Tolerability

During the study there were 119 adverse events among 76 participants. Adverse events occurred in peer educators (N=6), treatment as usual (N=31) and TTIM (N=40) participants. There were 3 deaths (2 TTIM, 1 treatment as usual). No adverse events were study-related as determined by a data safety monitoring board.

Primary Outcomes

Table 2 illustrates mean changes from baseline to 13, 30 and 60 weeks on mental illness symptom severity, functioning, general health, and DM control. For psychiatric symptoms, there was a significantly greater improvement over the 60-week follow-up in TTIM vs. treatment as usual in both CGI (p=<.001) and MADRS (p=.016). There was no significant difference on BPRS. Significant differences in the psychiatric symptom domain remained for CGI and MADRS after Bonferroni adjustment. On functioning, there was significantly greater GAF improvement at 60-weeks in TTIM vs. treatment as usual (p=.003) and a trend for SDS improvement (p=.086). Significant difference in functional status remained for GAF after Bonferroni adjustment. There were no significant group differences in SF-36 or HbA1c.

Secondary Outcomes Directly Related to DM Control

Change in DM knowledge was significantly better for TTIM versus treatment as usual (p<.001). Mean change from baseline to 13 weeks for TTIM was 8.47± 20.1, versus 0.11± 16.3 for controls (p<.02). At 60 weeks, TTIM continued to demonstrate a significant improvement in DM knowledge (5.97± 17.0) while treatment as usual showed a decline (-3.90± 16.7), (p<.001). There were no significant differences on DSCA.

Post-hoc evaluations

The sample had substantial baseline heterogeneity in DM control, and the study design did not require individuals to be at any specific threshold for HbA1c. While a target of HbA1c < 7.0 is recommended for non-pregnant adults with DM^35,36, Ismail-Beigi³⁷recently suggested that HbA1c targets should consider comorbidity and complexity. Specifically, psychological and social factors should be considered in approaching medical management of DM.^38,39This suggests that an appropriate (at least initial) HbA1c target for individuals with DM and comorbid serious mental illness might allow for more latitude compared to expected DM control in individuals without serious mental illness.⁴⁰

We conducted a post-hoc subgroup analysis comparing the effects of TTIM in patients with levels of HbA1c moderately above the guideline target for all patients (>7.5) versus those with better controlled HbA1c (≤7.5). This is consistent with the recommendation to take significant psychiatric comorbidities into account in setting HbA1c goals. There were 104 individuals with baseline HbA1c ≤7.5 (53% of the analyzable sample of 196). Two-sample non-parametric tests were used to investigate differences between patients in the lower HbA1c group who were exposed to TTIM versus treatment as usual. Individuals in TTIM had minimal change over the 30- and 60-week time periods in HbA1c (median increases of .00 and .10), compared to treatment as usual participants who had worsening of DM control (median increases of .25 and .50). These changes were significantly different between study arms at both 30-weeks (p= .048) and 60-weeks (p=.024). There continued to be a similar trend for better long-term maintenance of DM control in TTIM vs. treatment as usual participants at HbA1c levels that were still further above the ADA threshold. For individuals with baseline HbA1c ≤ 8 (N= 122, 62% of analyzable data), there were trends at both 30- and 60-weeks (p= .070 and p= .055) for TTIM participants to have better 60-week control compared to treatment as usual.

Patient satisfaction and feedback

Of 84 participants who responded to a post-TTIM group sessions satisfaction survey on TTIM acceptability, 98% (N= 82) strongly agreed or agreed that TTIM was useful. Most (95%, N= 80) strongly agreed or agreed that TTIM covered most of the important issues, while 92% (N=78) strongly agreed or agreed that TTIM addressed issues that are important to them.

Discussion

In this 60-week RCT, individuals with serious mental illness and DM who participated in the TTIM self-management approach had greater improvement in depression, global psychopathology and functioning compared to treatment as usual. Depression is associated with poor glycemic control and DM complications,^35,36so being able to improve mood and function in this high-risk group is clinically relevant. Glycemic control in the overall sample improved generally, and TTIM vs. treatment as usual group means did not differ significantly. However, in the 53% of the sample with baseline DM control that was at or modestly above ADA recommendations, post-hoc analysis found longer-term glycemic control better in the TTIM subgroup. This is a clinically important subgroup of the patients with serious mental illness, who might particularly benefit from use of this relatively low-burden approach to enhance usual care. TTIM participants, as a whole, demonstrated significant improvement in DM knowledge which was maintained during follow up, compared to treatment as usual where initial modest gains declined during follow-up. This is consistent with the theoretical basis of TTIM which focuses on knowledge acquisition and application.

Despite recent attention to the benefits of integrating mental and physical health services in people with serious mental illness, progress has been hampered by a variety of barriers.^41-45In Ohio, where this study was conducted, individuals with serious mental illness account for 22% of the Medicaid population while close to half (44%) of Medicaid expenditures in Ohio are for patients with serious mental illness and co-occurring chronic medical conditions⁴⁶. To address the multiple barriers to health management in serious mental illness, it has been suggested to apply both “top down” approaches that address systems-level problems (i.e. reimbursement models) as well as “bottom up” approaches which can actively engage patients. Self-management is a "bottom-up” approach that taps into a traditionally under-used resource—the power of an individual to promote his or her health. A strength of the TTIM trial is that it recruited relatively large numbers of minorities (54% African-American, 9% Hispanic), sub-groups known to be particularly at risk for both DM and DM-related complications^47-50.

The TTIM study is unique in that it included individuals with schizophrenia and bipolar disorder and used patients to deliver the intervention. In contrast, a study by Katon et al⁴⁹ that targeted depression and medical comorbidity excluded individuals with schizophrenia and bipolar disorder. A substantial proportion of the TTIM study sample was also on second-generation antipsychotic drugs, which are associated with metabolic abnormalities and diabetes. Standard diabetes education may simply not be enough as evidenced by the complications and early mortality seen in people with serious mental illness and comorbid DM. Our findings support the notion that partnering with patients to help deliver care can not only empower them, ²²butmay be a practical way to use the talents of individuals likely to be personally invested in helping others.

In our post-hoc analyses among individuals who had reasonably good baseline DM control (HbA1c ≤7.5), TTIM patients had less deterioration in HbA1c over 60-weeks compared to treatment as usual. It is not clear why individuals with poor baseline control of DM did not do better in TTIM vs. treatment as usual. Possibly, local changes in the safety net health system(i.e. Medicaid expansion)implemented during the time the study was being conducted promoted overall more aggressive DM management^50,51.Diabetes knowledge, which is believed to be critical to DM management, improved significantly more in the TTIM group. This indicator of an important intermediate goal may portend well for ultimate improvement on DM control. Some effective programs for people with serious mental illness include a focus on exercise and fitness⁵². Perhaps enhancing TTIM with exercise could be a future approach as was suggested by some TTIM participants.

There are a number of limitations to our study including the single-site location, lack of data about mental health treatments and completed phone contact information as well as the fact that psychotropic drugs were not a specific focus of intervention. Other limitations include possible effects of adverse events on study outcomes, even if not study-related, and the fact that a research sample may not entirely represent a real-world population. Strengths include the randomized design, safety-net setting, and large proportion of minorities. The study was rigorous in its primary analysis, including all subjects randomized regardless of session attendance. This first outcomes report focuses on overall change in symptoms, functioning, general health and DM control. Future analyses will address sample heterogeneity findings that may help inform the next generation of self-management interventions in serious mental illness.

In conclusion, a targeted self-management approach that taps into the power of patients to help themselves and which addresses psychiatric illness and DM concurrently can improve mental health symptoms and functioning and may be protective against loss of DM control in patients with reasonable DM control at baseline. The TTIM approach deserves further study given the extensive personal and financial burden of comorbidity in serious mental illness.