Abstract
BACKGROUND: Low-income older adults who live in subsidized housing have higher mortality and morbidity. We aimed to determine if a community paramedicine program — in which paramedics provide health care services outside of the traditional emergency response — reduced the number of ambulance calls to subsidized housing for older adults.
METHODS: We conducted an open-label pragmatic cluster-randomized controlled trial (RCT) with parallel intervention and control groups in subsidized apartment buildings for older adults. We selected 6 buildings using predefined criteria, which we then randomly assigned to intervention (Community Paramedicine at Clinic [[email protected]] for 1 yr) or control (usual health care) using computer-generated paired randomization. [email protected] is a paramedic-led, community-based health promotion program to prevent diabetes, cardiovascular disease and falls for residents 55 years of age and older. The primary outcome was building-level mean monthly ambulance calls. Secondary outcomes were individual-level changes in blood pressure, health behaviours and risk of diabetes assessed using the Canadian Diabetes Risk Questionnaire. We analyzed the data using generalized estimating equations and hierarchical linear modelling.
RESULTS: The 3 intervention and 3 control buildings had 455 and 637 residents, respectively. Mean monthly ambulance calls in the intervention buildings (3.11 [standard deviation (SD) 1.30] calls per 100 units/mo) was significantly lower (−0.88, 95% confidence interval [CI] −0.45 to −1.30) than in control buildings (3.99 [SD 1.17] calls per 100 units/mo), when adjusted for baseline calls and building pairs. Survey participation was 28.4% (n = 129) and 20.3% (n = 129) in the intervention and control buildings, respectively. Residents living in the intervention buildings showed significant improvement compared with those living in control buildings in quality-adjusted life years (QALYs) (mean difference 0.09, 95% CI 0.01 to 0.17) and ability to perform usual activities (odds ratio 2.6, 95% CI 1.2 to 5.8). Those who received the intervention had a significant decrease in systolic (mean change 5.0, 95% CI 1.0 to 9.0) and diastolic (mean change 4.8, 95% CI 1.9 to 7.6) blood pressure.
INTERPRETATION: A paramedic-led, community-based health promotion program ([email protected]) significantly lowered the number of ambulance calls, improved QALYs and ability to perform usual activities, and lowered systolic blood pressure among older adults living in subsidized housing. Trial registration: Clinicaltrials.gov, no. NCT02152891
In 2010, chronic disease accounted for 89% of worldwide deaths, mostly in older adults (65 years of age and older).1 It causes a substantial burden on health care systems, including high rates of ambulance calls.2 Poorly controlled and undiagnosed hypertension and diabetes are responsible for a substantial proportion of chronic disease burden among older adults.3,4 To reduce this burden, improved screening for risk factors is required.5,6 In addition, falls contribute to morbidity among older adults,7,8 especially those with low socioeconomic status.9
Morbidity from cardiovascular diseases, diabetes and falls frequently cause older adults to seek emergency medical care. With the percentage of older adults in Canada expected to increase from 14.6% (2012) to 24% (2036),10 it is critical that health promotion and preventive programs are evaluated for feasibility and effectiveness to inform future health systems policies.
Older adults with a lower socioeconomic status who live in subsidized housing have higher mortality rates,11 and poorer health-related quality of life (HRQoL)12 and health because of chronic diseases.13 Interacting psychosocial and physical factors complicate utilization of community and health care services, and are associated with development of chronic illness and disability.14 In Canada, older adults have difficulty accessing family physicians,14 and expansion of community paramedicine programs has been recommended.15
Community paramedicine is a new field in which paramedics provide health care outside of traditional emergency response.16,17 Community Paramedicine at Clinic ([email protected]) is a community-based health promotion and disease prevention program in subsidized-housing buildings for older adults.5 A pilot study of [email protected] in 1 subsidized building for older adults showed a substantial, clinically important 25% decrease in ambulance calls.5 The objective of our study was to use a randomized controlled trial (RCT) to determine if implementing [email protected] decreases mean ambulance calls (primary outcome) in intervention versus control buildings, measured at the building level. Secondary outcomes were improvement in risk-factor profiles and HRQoL among older adults living in subsidized community housing (individual-level measures and analysis).
Methods
Study design and setting
We conducted an open-label pragmatic cluster RCT with parallel intervention and control groups, in Hamilton, Ontario, between November 2014 and November 2016. The full RCT protocol has been published elsewhere.18 Intervention session staffing and daily operations were managed by Hamilton Paramedic Services. All operations were overseen by the McMaster Community Paramedicine Research Team, with advice from local stakeholders (Hamilton Paramedic Service, CityHousing Hamilton and City of Hamilton Housing and Public Health Services).
Participants
Within intervention buildings, participation in the [email protected] program was voluntary and accessible by all residents. We obtained written informed consent from participants before collecting any information. We considered data collected only from participants aged 55 years and older for analysis. For the secondary outcomes, we used convenience sampling to recruit survey participants from both intervention and control buildings via posters in common areas and mailed letters.
Inclusion and exclusion criteria
There were 2 levels of selection: building level and individual participants. Subsidized buildings managed by CityHousing Hamilton were selected using the following criteria: the building was 60% or more occupied by residents who are 65 years of age or older, had 50 or more apartment units, a matched building with similar characteristics was found, and had a unique postal code. From a total of 22 eligible buildings, 8 medium-to-large buildings (170–536 residential units) met the eligibility criteria and were matched into pairs (1:1) according to geography, number of units, proportion of older adults occupying the building, number of ambulance calls in the previous 2 years and social programming (Table 1). Participants for the pre- and postintervention survey were residents who were 55 years of age and older, who had lived in the building for at least 3 months.
Building-level characteristics for matched pairs
Intervention
Allocation of intervention occurred at the building level because the intervention was intended for all building residents. For each matched pair of buildings, we used computer-generated paired randomization (www.randomizer.org) to allocate 1 building to receive [email protected] for 1 year in addition to their usual health care and wellness programs (intervention), while the other building of the pair received usual health care and nonparamedic wellness programs in their building (control).
[email protected] is a weekly drop-in program that includes assessments of blood pressure, diabetes and risk of falls; health education and promotion; targeted referral to community resources; identification of patients at high risk and referral to health care; and regular communication of participants’ health information with their family physician.5,19 Sessions were held in a common building area by community paramedics who had undergone structured training (online interactive modules and webinar training). Paramedics on modified work assignments (pregnant or temporarily injured/disabled, who cannot perform full paramedic duties) implemented the program because they are well-suited for conducting risk assessments, as well as managing any emergencies that might occur in this vulnerable population.
Paramedics assessed participants using the Canadian Diabetes Risk Questionnaire (CANRISK),20,21 which was repeated at 6-month intervals. Participants with a moderate-to-high score on the questionnaire were asked to return for a fasting capillary blood glucose test.
Prespecified algorithms guided paramedics in directing participants to appropriate services. Participants at high risk were referred immediately to appropriate health care services. Participants at moderate risk were referred to community services to assist them in managing their health, specifically targeting risk factors for chronic disease, such as physical inactivity, unhealthy diet, tobacco use, harmful use of alcohol,22 mental health and stress. A second consent was required before a participant’s assessment results were sent by fax to their family physician; those without were referred to a local agency to help them obtain one. Individuals needing emergency medical attention were directed to urgent care or the emergency department by their own transport or ambulance, as appropriate.
Regular process evaluation assessed trial and implementation fidelity, efficiency, participation rates, compliance and ways to improve the program.
Outcomes
Our primary outcome was monthly ambulance calls at the building level per 100 apartment units. We collected data for our primary outcome from the paramedic service database. Building ambulance calls were standardized for a building with 100 apartment units to account for different building sizes. Hamilton Paramedic Service had reported an average volume of 3.67 calls per month per standardized building for older adults.
We assessed secondary outcomes (individual level) using the Health Awareness and Behaviour Tool,23 specifically developed for use with residents in social housing. It is a compilation of validated questionnaires used in Canada that evaluates health status, knowledge, behaviours and self-efficacy about cardiovascular disease and diabetes, and HRQoL (EQ-5D-3L24 converted to quality-adjusted life years [QALYs] using a Canadian value set25). Trained research staff conducted one-on-one interviews in English to complete questionnaires with participants who volunteered. A $10 gift card was provided. Our secondary outcomes also included changes in risk factor measures (physical activity, fruits and vegetable intake, body mass index [BMI], waist circumference, HRQoL domains and QALYs.) Body mass index was calculated from self-reported height and weight measured using a scale. Waist circumference was collected using a measuring tape placed at the naval level; if the individual refused, their pant size was requested.
Sample size
Detecting a difference of 25% (0.92 ambulance calls per standardized building per mo) between intervention and control groups (α = 0.05, β = 0.8, binomial test) required a sample size of 28. This effect size is feasible because the pilot study showed a 25% reduction in calls.26 Because the intervention ran for a 12-month period, the study required 2.3 buildings to provide 28 data points (monthly calls). Because no data were available for estimating an intracluster correlation (ICC) for within-building clustering of monthly ambulance call volume, we used a conservative sample size of 4 intervention buildings and 4 control buildings. There was no published minimum clinically important difference for ambulance calls. Therefore, we consulted with experts at the Hamilton Paramedic Service and determined that 10% would be an important call reduction.
For our secondary individual outcomes, we estimated the sample size using the CANRISK category, because this was the most representative of overall health behaviour. For a difference of 20%, we needed a minimum of 97 participants from the intervention and control groups (α = 0.05, β = 0.8, difference between proportions).
Statistical analysis
We report methods and results in accordance with the CONSORT extension to cluster RCTs.27 We used descriptive statistics to analyze baseline characteristics of both the clusters and participants. We conducted two levels of analysis: building level (primary outcome: mean monthly ambulance calls) and individual level (secondary outcomes: risk assessments, risk factors, HRQoL).
For the primary outcome, we used generalized estimating equations analysis, adjusted for each building’s ambulance call numbers at baseline (1 yr before the intervention) and controlled for the pairing of the buildings.28 We conducted 2 sets of analyses: in the first analysis, we included 3 pairs of buildings with reliable data (final analysis) and, for the second analysis, we included all randomly assigned buildings, despite 1 building having unreliable data (sensitivity analysis).
For the secondary outcomes, we used general estimating equations for comparing risk factor changes between intervention and control groups, and adjusted for building pairs and clustering by buildings. We performed intention-to-treat principle analysis using multiple imputation to account for missing data owing to dropout or loss to follow-up of participants.29,30 We conducted 1 full analysis that included all participants who were present during the pre-intervention period. In addition, we performed 2 subgroup analyses: the first subgroup analysis involved only residents of intervention buildings who attended the [email protected] sessions versus the residents of control buildings, with imputation for those with missing data; and the second involved the same comparison but included only participants with post-intervention data.
We used hierarchical linear modelling to assess within individual changes in blood pressure (controlling for clustering of individuals by building) and to identify significant changes across 10 visits via post hoc analysis using least significant differences. All analyses were performed using SPSS version 20 and STATA version 11.
Ethics approval
This study was approved by the Hamilton Integrated Research Ethics Board.
Results
Of 22 subsidized-housing buildings for older adults managed by CityHousing Hamilton, 8 buildings met our eligibility criteria, providing 4 matched pairs (Figure 1). Characteristics of the matched building pairs are presented in Table 1. Initially, we included building pairs; however, we excluded 1 pair from final analysis because of an unanticipated inability to obtain the ambulance call data (there was an assisted-living residence adjoined to 1 of the buildings, which we thought could be excluded from ambulance call data, but we discovered post hoc that this was impossible). This came to light soon after the start of the study; however, we decided to continue providing the intervention program to those residents.
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Participant survey and 1-year follow-up. *Most postintervention outcome data for all participants who moved were still available from the [email protected] database. Note: [email protected] = Community Paramedicine at Clinic, HABiT = Health Awareness and Behaviour Tool.
The intervention and control buildings had 455 and 637 residents, respectively. The mean participation rate for [email protected] in the intervention buildings was 37.6% (n = 171), ranging from 14% to 52% across buildings.
In both the intervention and control buildings, 129 residents participated in the preintervention Health Awareness and Behaviour Tool survey (Figure 1) to measure the secondary outcomes. Of the residents in the intervention buildings who attended [email protected] (n = 65), 59 (90.8%) completed the postintervention survey and 6 (9.2%) either moved or died during the study period. Of those who did not attend [email protected] (n = 64), 19 (29.7%) completed the postintervention survey, 20 (31.2%) moved or died and 25 (39.1%) were lost to follow-up. In the control buildings, 59 residents (45.7%) completed the postintervention survey, 25 (19.3%) moved or died and 45 (34.9%) were lost to follow-up. CityHousing Hamilton provided aggregate information about moves and deaths.
Most individual-level sociodemographic and risk factors were similar between the intervention and control groups (Table 2). Smoking rates across the intervention and control buildings differed despite random selection. Other lifestyle-related similar factors did not differ across groups. Baseline characteristics indicated that this population had numerous health-related problems and risk factors. We found that almost half had low education levels, 80% had inadequate health literacy, more than 50% had hypertension and more than 23% self-reported diabetes. Among those without diabetes, nearly all had moderate-to-high risk of developing diabetes, and most had modifiable risk factors. Indicators for HRQoL showed that more than 50% had problems with mobility, pain or discomfort, and anxiety or depression.
Participant-level characteristics for intervention and control buildings at baseline
Primary outcome
There was a significant difference (p
Difference in monthly ambulance call rates between intervention and control buildings
Secondary outcomes
In the intention-to-treat analysis for all participants who completed the survey during preintervention (Table 4, Table 5). almost all measures were in favour of the intervention participants. Significant differences were noted for QALY and the HRQoL domain measuring ability to engage in “usual activities” (p p p
Change in health behaviour and quality-of-life outcomes between participants in intervention and control buildings*
Comparison of changes in health indicators among participants who attended [email protected] and participants in control buildings*
Change in health behaviour and quality-of-life outcomes between participants in intervention buildings who attended [email protected] and those in control buildings*
Comparison of changes in health indicators among participants who attended [email protected] and participants in control buildings*
Thirteen (20.6%) out of 63 participants in the intervention building with high scores for CANRISK had elevated capillary blood glucose levels (≥ 7.0 mmol/L), whereas 1 (3.6%) out of 28 participants with moderate scores had an elevated capillary blood glucose level. This suggests that 14 residents potentially had undiagnosed diabetes, and up to 50 were at high risk of diabetes developing within 10 years.
Out of all participants who attended [email protected], 111 (53.9%) had elevated blood pressure (≥ 140/90 mm Hg) during their first visit. Thirty-six participants (52.5%) with no previous diagnosis of hypertension and 75 participants (54.7%) of those previously diagnosed with hypertension had elevated blood pressure. While attending [email protected], mean blood pressure for these participants decreased significantly by 5.0 mm Hg systolic (95% CI 1.0 to 9.0, p p
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