Screening and Intervention for Suicide Prevention: A Cost-Effectiveness Analysis of the ED-SAFE Interventions

Abstract

Suicide is the tenth leading cause of death in the United States and imposes substantial economic costs. Studies suggest that suicide screening followed by an intervention may be effective at identifying suicidal individuals and preventing recurring self-harm, but few cost-effectiveness studies have been conducted to determine whether the increased costs of screening and intervention are justified by improvements in patient outcomes. This study provides a cost-effectiveness analysis of universal screening plus intervention implemented within a hospital emergency department (ED) to prevent suicides and reduce self-harm behavior. Participants (n=1,339) were recruited in eight EDs located across the United States between August 2010 and November 2013. The participating EDs ranged from small community hospitals to large academic center hospitals, and these sites sequentially implemented two study interventions—universal screening combined with treatment as usual and universal screening plus intervention—that were compared to treatment as usual. Our study demonstrates the cost-effectiveness of these interventions, relative to treatment as usual, in detecting and reducing suicide acts 12 months post ED visit. Costs of implementing universal screening plus intervention were $1,063 per participant, approximately $500 more per participant than universal screening with treatment as usual. Although more costly, universal screening plus intervention was more effective relative to universal screening and treatment as usual for the suicide outcome. While the choice of universal screening plus intervention depends on the value placed on the outcome by decision makers, our results suggest that there could be potential for significant cost savings in implementing such suicide prevention measures.

INTRODUCTION

Suicide is the tenth leading cause of death in the United States and imposes substantial economic costs with estimates associated with suicide and suicide attempts around $95 billion annually (1–2). This substantial social and economic toll has prompted calls for more research and intervention to help prevent suicide and self-harm behaviors. Attention has been focused on emergency departments (EDs) as a currently underutilized location for suicide prevention efforts 3–4). In the United States, approximately 500,000 suicide-related visits to the ED occur annually and up to 25% of individuals presenting for suicide attempts in the ED will make another attempt (5–6).

Few studies have examined screening and intervention as a suicide prevention (7, 8, 9, 10, 11), and findings from these studies suggest that screening and follow-up interventions may be effective and/or cost-effective relative to usual care. For example, Denchev and colleagues estimated the expected cost-effectiveness of three outpatient interventions (i.e., follow-up postcards and care letters, follow-up telephone outreach, and suicide-focused cognitive behavioral therapy) to reduce suicide risk among individuals presenting at hospital EDs relative to usual care. They found each of these interventions to be cost-effective relative to usual care, assuming a willingness to pay ≥$50,000 per life year. This study aims to add to the knowledge base by analyzing the cost-effectiveness of suicide screening and intervention implemented as part of a larger suicide prevention study— the Emergency Department Safety Assessment and Follow-up Evaluation (ED-SAFE) study.

ED-SAFE STUDY DESIGN

Participants in the ED-SAFE study were recruited in eight general EDs across seven U.S. states from August 2010 through November 2013 (12). The participating EDs ranged from small community hospitals to large academic center hospitals (13). The sites were randomly assigned to one of four cohorts with each cohort assigned to a different start date from which they progressed through three study phases sequentially. The three phases included: treatment-as-usual (Phase 1); universal screening (Phase 2); and universal screening + intervention (Phase 3).

In the treatment as usual phase, participants were screened and treated per the ED’s existing suicide-related protocols to establish a study baseline and comparison group. In the universal screening phase, a universal screening protocol for suicidality was implemented by ED nurses. The universal screen, the Patient Safety Screener-3 (PSS-3), was a 3-item measure that assessed depressed mood, active suicidal ideation in the past two weeks, and lifetime suicide attempt (12).

In the universal screening + intervention phase, screening was enhanced by adding an assessment of the level of suicide risk through a physician-led secondary suicide risk assessment for patients who screened positive on the PSS-3. The intervention included the provision of a self-administered personal safety plan (a structured tool to identify early warning signs for suicidal behavior and internal and external coping resources) mental health treatment information and suicide hotline resources at ED discharge. Following discharge, universal screening + intervention phase participants were contacted through a series of telephone calls. These intervention telephone calls were based on the Coping Long Term with Active Suicide Program (CLASP) protocol and modified for use with ED patients (14). CLASP-ED telephone calls were provided by a centralized team of psychologists and counselors which served all eight EDs. Each participant who screened as needing the intervention was eligible to receive up to seven telephone sessions while a participant’s significant other or family member was eligible to receive up to four telephone sessions. These sessions were spread out over the course of one year. The sessions evaluated current suicide and psychological status and reviewed the patient safety plan (12).

Study participants were enrolled in the ED-SAFE study by research assistants at each ED site. Individuals with any level of harm ideation or behavior upon entry to the ED were eligible to be approached for study inclusion. Across all phases, 1,376 participants were enrolled of which 1,339 had sufficiently complete data to be included in the cost-effectiveness analysis. Only 3% of enrolled participants were excluded due to missing data which was proportionally distributed over the three phases.

METHODS

Cost Estimates

Screening and intervention costs were calculated from the provider perspective (i.e., the hospital ED) to provide critical information to entities evaluating whether they should expand suicide prevention services. We worked with the study’s clinical staff, from December 2011 to June 2016, to identify clinical activities typically performed as part of the screening and intervention. The economic study was deemed not human subject research and waived by IRB. We did not include costs incurred by other entities or costs incurred by patients (e.g., travel costs). We also did not include costs associated with research activities since these activities were not part of real-world clinical care. We used a micro-costing approach and collected cost data at the activity level from each site for each study phase. This information was collected through two telephone interviews with each site’s principal investigator, other ED administrative staff or research assistants as needed, and supervisory staff performing the CLASP-ED component.

Data on resources used to perform the activities were combined with price data such as hourly wages and rents to produce a total unit cost estimate for each activity. Hourly wages and other salary data were collected for each staff type and, if a specific staff wage was not available, we used the mean hourly wage for that staff type from the Bureau of Labor Statistics Wage Data by Metropolitan Area (http://www.bls.gov/oes/current/oessrcma.htm) adjusted to 2015 U.S. dollars using the Consumer Price Index. Space costs were estimated using an average rental rate for medical and hospital office space where each site was located as obtained from real estate listing found on LoopNet (www.loopnet.com) and cross-referenced with findings from the Newmark Grubb Knight Frank National Office Market Report (15).

The activities performed for each patient were multiplied by the estimated unit cost for each activity to produce a cost per patient by site and phase. The quantity of activities performed for each patient was tracked as part of the ED-SAFE study through chart reviews of the patient’s index ED visit. Summing across patients within a phase and site yields the total cost of the phase at a site. We then calculated the average across sites to get an average cost for each phase at the site level. All costs are calculated in 2015 U.S. dollars (2015 $).

Cost-Effectiveness Analysis

Effectiveness Measures (Screening and suicide outcomes)

Screening outcomes measures for the cost-effectiveness analysis included percentage of ED patients screened for suicide risk and percentage of ED patients who screened positive for suicide risk. These measures were developed using screening data from the study’s screening log database that included nearly 250,000 patients entering the eight ED sites during each phase of the ED-SAFE study. For each site, the percentage of ED patients screened was calculated by dividing the number of screened patients at the ED site by the total number of patients entering the ED site during the relevant phase. Because the universal screening approach was the same in the universal screening and universal screening + intervention phases, the percentage of clients screened was averaged across these two phases to calculate a single value for percentage of patients screened for each site that was compared to each site’s treatment as usual screening percentage. A similar calculation was done for the percentage of patients who screened positive.

Suicide outcome measures included a suicide composite measure that included any suicide attempts or death by suicide over the 12 months following the index ED visit (14). This measure was operationalized as patient-level counts of the number of suicidal acts over the 12-month period following the index ED visit.

Following the methodology used in the study’s main suicide outcome paper, we calculated predicted values for the number of suicidal acts with a negative binomial model to account for over-dispersion in the outcome (16). Each model included categorical variables for study phase, and dichotomous variables for ED site. The model also included several patient-level variables representing patient demographics and baseline status (16).

Cost-Effectiveness

Separate cost-effectiveness analyses were performed to compare the three phases across the screening and suicide outcome effectiveness measures. In each case, we calculated an incremental cost-effectiveness ratio (ICER) which combined differences in cost and effect between the phases (17). We first ranked the phases in increasing order of average cost. The ICER was then computed as the difference in average cost divided by the difference in average effectiveness.

For the screening measures, we examined use of a universal screen relative to treatment as usual. We divided the ED sites into two groups—those sites without any screen prior to the study (n = 4) and those sites with an informal, non-universal screen prior to the study (n = 4) and conducted separate cost-effectiveness analyses for each group. This allowed us to examine the cost-effectiveness for going from no screening to universal screening and going from an informal non-universal screen to universal screening. An informal screen was defined as using a set of non-standardized questions to determine suicidal ideation or behavior, and, therefore, these screens were not equivalent to universal screening. Costs used for these analyses were the average screening costs per month per site.

For the suicide outcome measure, we examined universal screening + intervention relative to universal screening and treatment as usual with all eight ED sites included in the analysis. For these analyses, we used total phase costs per patient.

Cost-Effectiveness Acceptability Curves

We calculated a cost-effectiveness acceptability curve (CEAC) to show the probability that a given phase is the cost-effective option as a function of a decision maker’s willingness to pay (WTP) for the suicide composite outcome. The CEAC incorporates the joint variability of the cost and effectiveness estimates and allows us to better capture the variability in our cost-effectiveness analysis in lieu of confidence intervals for the ICERs (18–19). We used a nonparametric bootstrap method to calculate the CEAC that compares the phases for the suicide outcome measure.

RESULTS

Screening

Table 1 presents costs and outcomes associated with the addition of universal screening for four sites without a formal screen in the treatment as usual phase. As shown, the average percentage of patients screened substantially increased moving from treatment as usual to the universal screening —from 8% to 71% (p < 0.01). The percentage of patients screening positive for suicidality also increased from 3.3% to 6.8% (p < 0.05). The addition of universal screening was associated with an average increase in monthly site-level costs of $604 (p< 0.05). Taking the increase in costs ($604) over the change in screening rates (71% - 8%) yields an ICER of approximately $10 per one percentage point increase in monthly screening rate. Similarly, the ICER comparing universal screening to treatment as usual for the percentage of patients who screen positive for suicidality was approximately $174 per percentage point increase in the rate of individuals who screen positive for suicidality.

Table 1.

Screening Costs and Outcomes: Cost-effectiveness (CE) results for sites without formal screens during Treatment as Usual (n=4) (2015 $)

Phase	Average percent of ED patients screened for suicidality or self-identified as suicidal (Mean)	SE	pa	Average percent of ED patients screened positive for suicide risk (Mean)	SE	pa	Average monthly cost of screening ED patients (Mean)	SE	pa	Incremental CE Ratiob: $ per percentage point increase in screening rate (ΔC/ΔE)	Incremental CE Ratio: $ per percentage point increase in positive screening rate (ΔC/ΔE)
Treatment as usual without formal screensc (Phase 1)	8%	2.7	-	3.32%	0.50	-	-d	-	-	-	-
Universal screen added ED-SAFE screen (Phases 2 + 3)	71%	7.4	<0.01	6.80%	0.91	<0.01	$604	99.9	<0.05	$9.59	$173.56

^aSignificant difference determined by paired t-test

^bIncremental CE Ratios (ICERs) are calculated from the average cost and mean effectiveness presented in the table.

^cFormal screen refers to a standardized tool, such as the PSS-3 or other standardized set of questions, that was used during ED triage.

^dIn the TAU phase, these sites did not have a formal screening process, and therefore, screening costs were not estimated. ED sites without formal screens depended on patients self-identifying as suicidal or the triage nurses’ observations.

Notes: ED = Emergency Department | SE = Standard Error

Table 2 presents results for those ED sites that already had informal screening approaches prior to the implementation of universal screening. These sites increased their screening rates by 46 percentage points—from 37% to 83% (p < 0.10). They also increased the percentage of patients who screened positive by approximately 2 percentage points—from 2.7% 4.8% (n.s.) The increase in costs is $215 (p < 0.10). For overall screening rates, incremental cost-effectiveness ratio for universal screening relative to treatment as usual is approximately $5 per one percentage point increase in monthly screening rate. For positive screens for suicidality, the ICER is approximately $106 per one percentage point increase in the rate of individuals who screen positive for suicidality.

Table 2.

Screening Costs and Outcomes: Cost-effectiveness (CE) results for sites with non-universal screens during Treatment as Usual (n=4) (2015 $)

Phase	Average percent of ED patients screened for suicidality or self-identified as suicidal (Mean)	SE	pa	Average percent of ED patients screened positive for suicide risk (Mean)	SE	pa	Average monthly cost of screening ED patients (Mean)	SE	pa	Incremental CE Ratiob: $ per percentage point increase in screening rate (ΔC/ΔE)	Incremental CE Ratio: $ per percentage point increase in positive screening rate (ΔC/ΔE)
Treatment as usual with non-universal screensc (Phase 1)	37%	19.8	-	2.73%	0.15	-	$487	357.7	-	-	-
Universal screen changed to ED-SAFE screen (Phase 2 + 3)	83%	4.7	<0.1	4.75%	0.51	ns	$702	203.1	<0.1	$4.67	$106.44

^aSignificant difference determined by paired t-test

^bIncremental CE Ratios (ICERs) are calculated from the average cost and mean effectiveness presented in the table.

^cNon-universal screen refers an ED site which used a standardized screening tool or set of questions to assess patient suicidality but only if an ED triage nurse suspected a patient may be suicidal.

Notes: ED = Emergency Department | SE = Standard Error

Participants

The median participant age was 37 years with 56% women. Sixty-seven percent of participants were non-Hispanic White, 15% were non-Hispanic African American, 12% were Hispanic, and 5% identified as non-Hispanic other. Over 70% of the sample had a history of previous suicide attempts and over one-third had made an attempt in the week prior to the ED visit (16).

Suicide

As shown in Table 3, the average per-patient costs for treatment as usual and the universal screening phase were estimated as $513 and $566 per month, respectively. Universal screening + intervention costs significantly more at $1,063 per patient per month (p < 0.01) with the addition of the telephone sessions driving this increase. The universal screening + intervention phase is also more effective in averting suicide attempts and deaths by suicide relative to both universal screening and treatment as usual. Similarly, the universal screening phase is more costly but more effective relative to treatment as usual, although this cost difference is not statistically significant. Moving from treatment as usual to universal screening decreased the average number of averted suicide attempts and deaths by suicide by approximately 0.02 (0.454–0.435, n.s.), increased cost of $53 (n.s.) and yielded an ICER of $2,789 per averted suicide attempt or death by suicide over the 12 months post-ED visit. Moving from universal screening to universal screening + intervention further decreased suicide attempts and deaths by 0.099 (0.435–0.336, p < 0.01), increased costs by $497 (p < 0.01), yielding an ICER of $5020 per averted suicide attempt or death by suicide (see online Appendix 2 for incremental scatterplots).

Table 3.

Cost and Cost-Effectiveness Results for the Suicide Outcome (2015 $)

Treatment Arm	N	Average Cost of ED Services and Intervention (Mean)	SE	pa	Mean Number of Attempts and Deaths by Suicide (Mean)	SE	pa	Cost per Additional Suicide Attempt/Death by Suicide Avertedb (ΔC/−ΔE)
Treatment as usual (Phase 1)	486	$513	30.47	--	0.454	0.015	--	-
Universal screen (Phase 2)	362	$566	44.66	ns	0.435	0.016	ns	$2,789
Universal screen + intervention (Phase 3)	491	$1,063	22.82	<0.01	0.336	0.012	<0.01	$5,020

^aSignificant difference determined by t-test between universal screen and universal screen + intervention

^bCalculated from the average cost and mean effectiveness presented in the table.

Notes: ED = Emergency Department | SE = Standard Error

Figure 1 includes the CEACs for the number of suicides attempts or death by suicide. The CEACs show the probability that a phase is cost effective relative to alternatives for a given willingness-to-pay amount. The treatment as usual and universal screening phases have the highest probability of being cost-effective for low willingness-to-pay values (< $5,000). However, once the willingness-to-pay amount is greater than $5,000, universal screening + intervention has the highest probability of being cost-effective and this probability is greater than 80% for willingness-to-pay values exceeding $6,000. If a decision maker is willing to pay over $6,000 then the universal screening + intervention phase has the highest probability of being cost-effective and is their optimal choice.

Figure 1.

Probability that a Phase (Intervention) is Cost-Effective in Preventing Suicide Attempts or Deaths by Suicide

DISCUSSION

Suicide detection and prevention efforts that target individuals presenting at EDs are a critical component in reducing suicide acts and death by suicide given the high number of suicide-related ED visits that occur annually in the United States. Understanding the cost-effectiveness of these services can aid in their implementation and dissemination as well as in the development of further suicide prevention efforts.

Implementing universal screening increased average costs between $215 and $604 dollars per month depending on whether the ED already had an informal screening process in place. However, with the increased use of universal screening the percentage of participants screened and the percentage of participants who screened positive for suicide risk increased. The calculated ICER shows that it costs about $106 to $174 per percentage point increase in the monthly screened positive rate.

These results suggest that universal screening may be a cost-effective screening intervention relative to treatment as usual. However, once a patient is positively identified with suicidal risk, a cost-effective treatment is needed. Universal screening + intervention showed a reduction in the per-person number of suicide attempts and death by suicide relative to treatment as usual and universal screening. The effectiveness study conducted in Miller et al. (15) showed that these results are statistically significant. However, this reduction comes at a cost, with universal screening + intervention per-participant costs almost double those of treatment as usual and universal screening. While universal screening + intervention costs more than treatment as usual and universal screening, the increased effectiveness suggests that universal screening + intervention may be more likely to be the optimal choice among these three alternatives. Our analysis shows that for willingness-to-pay values above $5,000 per suicide attempt or death by suicide, universal screening + intervention has the highest probability of being the cost-effective choice.

For the suicide outcome with an estimated ICER of $5,020 per averted suicide attempt or death by suicide it is possible to illustrate the potential cost savings of the universal screening + intervention with existing literature. We focus on suicide attempts because, although deaths by suicide were captured in our data, they were a rare event within the study follow-up period. Shepard (2) estimates the annual cost of nonfatal attempted suicides in the United States at $5.34 billion (2015 dollars) with 395,000 suicide attempts officially reported annually. Calculating a per-person cost yields an estimate of $13,522 annually. Therefore, universal screening + intervention yields a cost savings of $8,497 per averted suicide attempt from a societal perspective ($13,522-$5,025). Based on the annual 395,000 reported suicide attempts, if even just 25% of these attempts were averted each year through use of universal screening + intervention, society would benefit by cost savings of $839 million annually. These results show that the combination of suicide screening in the ED and a post-ED intervention for those who screen positive provides both economic and clinical value to society (15).

Our study has a few limitations. First, we relied on the study PIs’ judgment as to which activities are primarily research-related and which would be used in best ED practice. Furthermore, study PIs provided data on labor time needed to complete activities in each phase rather than relying on time logs or other mechanisms for direct measurement as these approaches were deemed too burdensome for the ED staff. Second, we did not include all the costs associated with administrating a universal screening such as ongoing training and quality control measures (e.g., record checks). Finally, our analysis is conducted in the context of an ED; the effectiveness and cost estimates presented here are unlikely to apply in other clinical settings.

Despite these limitations, our study makes an important contribution to the literature by providing further economic evidence of the value of suicide screening and intervention in an ED setting. Our study demonstrates the potential cost-effectiveness of both universal screening and intervention relative to treatment as usual in detecting and reducing suicide acts at 12 months post-ED visit. While the choice of universal screening and intervention as an economically optimal intervention depends on the value placed on these outcomes by decision makers, our results suggest that there is the potential for significant societal cost savings in implementing such suicide prevention measures.

• A universal screen for suicidality in emergency departments increases costs while increasing the percentage of patients identified at risk for suicide.

• A universal screen combined with a telephone-based intervention with those at risk for suicide costs about 50% ($500) more per participant while reducing the number of suicide attempts and deaths about 10% (0.1) 12-months post ED.

• Universal screening + intervention post ED discharge is likely to be cost-effective if the willingness-to-pay is over $5,000 per averted suicide attempt or death.

• Based on the annual 395,000 reported suicide attempts, if even just 25% of these attempts were averted each year through use of universal screening + intervention, society would benefit by cost savings of $839 million annually.