Assessing the impact of food insecurity on HIV medication adherence in the context of an integrated care programme for people living with HIV in Vancouver, Canada

Abstract

Objective:

Food insecurity, or self-reports of inadequate food access due to limited financial resources, remains prevalent among people living with HIV (PLHIV). We examined the impact of food insecurity on combination antiretroviral therapy (cART) adherence within an integrated care programme that provides services to PLHIV, including two meals per day.

Design:

Adjusted OR (aOR) were estimated by generalized estimating equations, quantifying the relationship between food insecurity (exposure) and cART adherence (outcome) with multivariable logistic regression.

Setting:

We drew on survey data collected between February 2014 and March 2016 from the Dr. Peter Centre Study based in Vancouver, Canada.

Participants:

The study included 116 PLHIV at baseline, with ninety-nine participants completing a 12-month follow-up interview. The median (quartile 1–quartile 3) age was 46 (39–52) years at baseline and 87 % (n 101) were biologically male at birth.

Results:

At baseline, 74 % (n 86) of participants were food insecure (≥2 affirmative responses on Health Canada’s Household Food Security Survey Module) and 67 % (n 78) were adherent to cART ≥95 % of the time. In the adjusted regression analysis, food insecurity was associated with suboptimal cART adherence (aOR = 0·47, 95 % CI 0·24, 0·93).

Conclusions:

While food provision may reduce some health-related harms, there remains a relationship between this prevalent experience and suboptimal cART adherence in this integrated care programme. Future studies that elucidate strategies to mitigate food insecurity and its effects on cART adherence among PLHIV in this setting and in other similar environments are necessary.

Advances in combination antiretroviral therapy (cART) have improved morbidity and mortality for people living with HIV (PLHIV)^(1–3). However, social and structural barriers, such as food insecurity (FI), homelessness, and poverty continue to prevent marginalized PLHIV from fully benefiting from cART^(4–6). Notably, FI, or self-reports of uncertain or inadequate food access due to limited financial resources, is associated with adverse HIV-related clinical outcomes^(7–9); FI has a known association with incomplete HIV viral load suppression^(10,11), lower CD4 cell counts⁽¹²⁾ and a heightened risk for mortality^(4,13).

Research has suggested that the impact of FI on adverse HIV-related outcomes is due, in part, to its negative association with adherence to cART^(9,14,15). A study based in San Francisco revealed that PLHIV who were food insecure were almost half as likely to be adherent to cART than their food-secure counterparts⁽¹¹⁾. Additional research has illustrated mechanisms through which FI may impact cART adherence^(16–19). For example, individuals may skip doses or discontinue treatment to mitigate the actual or anticipated side-effects of taking cART without food (e.g. nausea, stomach pain)^(9,16).

While past studies have established a link between FI and suboptimal cART adherence^(16,18,20), this relationship has yet to be explored within the context of integrated care programmes that aim to attenuate the consequences of socio-structural inequities among PLHIV. For example, the Dr. Peter Centre (DPC) is an integrated care programme serving PLHIV in Vancouver, British Columbia (BC), Canada. PLHIV are eligible to access DPC programming if they are at risk of health deterioration and demonstrate a need (e.g. limited financial or social supports) for assistance to maintain independence⁽²¹⁾. The DPC aims to reduce barriers to access and retention in HIV care by offering a wide array of harm reduction services⁽²¹⁾. These services include counselling, therapies (e.g. art, music, recreational), nursing (e.g. wound care, foot clinic, cART support) and amenity access (e.g. nap room, showers)⁽²¹⁾. DPC clients can also access two nutrient-rich meals per day, including balanced portions of meat/alternatives, dairy products, fruits and vegetables, and whole grains⁽²²⁾. While we acknowledge that food provision does not directly address the root cause of FI in resource-rich settings, which is inadequate financial resources^(23,24), we hypothesize that this service, along with other supports that are offered in this setting, may help mitigate the relationship between FI and cART adherence. Therefore, we undertook a study to examine this relationship among clients of the DPC. Further understanding this relationship within an integrated care setting may have implications for optimizing HIV care among structurally vulnerable PLHIV.

Methods

The present study used data from a community-based observational study exploring the impact of the DPC’s services on health outcomes and HIV-related care for marginalized PLHIV. The quantitative study, described in detail elsewhere^(21,25), is comprised of a longitudinal cohort of DPC clients who participated in baseline (n 121) and follow-up (n 102) socio-behavioural surveys. Participant recruitment was conducted by peer research associates (i.e. individuals with common experiences to DPC clients) and DPC staff. Study invitations were placed at the DPC reception desk and included the study coordinator’s number, whom participants could call if interested in participating.

Individuals were eligible for the current analysis if they had been enrolled as a DPC client after 27 February 2011, had completed a baseline survey and were on cART at baseline. Baseline surveys that collected sociodemographic, behavioural and FI-related data were administered by the peer research associates to the DPC clients between February 2014 and March 2016. Follow-up surveys were conducted approximately 12 months after the baseline surveys. Participants received $CAN 30 honoraria as compensation for their involvement.

Survey data were supplemented with comprehensive clinical data from the HIV Drug Treatment Program (DTP) held at the BC Centre for Excellence in HIV/AIDS. The DTP provides cART free-of-charge to all PLHIV in the province of BC⁽²⁶⁾. As described in detail elsewhere, individuals are enrolled in the DTP when they are first prescribed cART by any physician in BC and all subsequent measures of HIV-related clinical variables (e.g. CD4 count, HIV viral load, cART refill compliance) are stored in the DTP database⁽²⁶⁾. Because our analysis required that DPC clients be on cART at baseline, all the participants in the present study were enrolled in the DTP.

Measures

The primary explanatory variable of interest was FI in the past 12 months, which was measured using the ten-item adult scale of Health Canada’s Household Food Security Survey Module (HFSSM)^(27,28). This tool classifies FI status based on the number of affirmative responses to the ten items. In accordance with Health Canada’s guidelines, zero or one affirmative response on the HFSSM indicates food security, while two or more affirmative responses denotes FI⁽²⁸⁾.

The outcome variable of interest for the current analysis was cART adherence, based on refill compliance, which is a previously validated method of estimating adherence when direct observation of medication consumption is not feasible⁽²⁹⁾. Refill compliance is calculated as the number of days that cART was dispensed divided by the number of days of follow-up during the 12 months prior to the interview date^(30,31). This measure was expressed as a percentage and dichotomized as optimal (adhering to ≥95 % of prescribed cART) or suboptimal (adhering to <95 % of prescribed cART) adherence; this cut-off has been validated as having clinical relevance for HIV viral load suppression^(31,32). Potential confounding variables for inclusion in the statistical models were selected a priori based on their hypothesized relationship with FI (exposure) and cART adherence (outcome).

Data analyses

Descriptive P values were calculated using Pearson χ² tests and Wilcoxon rank-sum tests for binary/categorical variables and continuous variables, respectively. Adjusted OR (aOR) were estimated by generalized estimating equations, quantifying the relationship between binary FI (food secure v. moderate/severely food insecure) and binary cART adherence (adhering to <95 % of prescribed cART v. adhering to ≥95 % of prescribed cART) with logistic regression^(33,34). Generalized estimating equations were used to account for the longitudinal nature of the baseline and follow-up measures taken from individual participants using an exchangeable correlation structure with robust se^(35,36). To select the variables for the multivariable model, a change-in-estimate approach to confounder selection was used^(37,38). Specifically, if the coefficient for FI changed by less than 5 % after the omission of a given confounder, the variable was not adjusted for in the final model^(37,39). All data were analysed using the statistical software package SAS version 9.4.

Results

Among the 121 DPC clients in the total cohort, 116 individuals and 215 total visits (observations) were included in the current analysis after excluding those who were not on cART at baseline or who were missing data on the FI or cART adherence measures. Table 1 reveals no significant differences in the proportions of responses to the HFSSM questions or overall FI status between baseline and follow-up. As shown in Table 2, at baseline, 74 % (n 86) of participants reported experiencing FI in the past 12 months and 67 % (n 78) of participants were adherent to cART in the past 6 months. The median (quartile 1–quartile 3) age of participants at baseline was 46 (39–52) years and 87 % (n 101) of participants were biologically male at birth. Notably, 35 % (n 41) identified as Indigenous, 70 % (n 81) had been diagnosed with hepatitis C and 53 % (n 62) had used illicit drugs (excluding marijuana) in the past 6 months.

Table 1.

Baseline and follow-up responses to the ten-item adult scale of the Household Food Security Survey Module (HFSSM) of Dr. Peter Centre clients in Vancouver, Canada (February 2014–March 2016)

HFSSM item	Response options	Baseline response (n 116)		Follow-up response (n 99)		P value
		n	%	n	%
1. You and other household members worried that food would run out before you got money to buy more. Was that often true, sometimes true, or never true in the past 12 months?	Often true*	38	34·23	35	35·71
	Sometimes true	37	33·33	32	32·65
	Never true	36	32·43	31	31·63	0·975
2. The food that you and other household members bought just didn’t last, and there wasn’t any money to get more. Was that often true, sometimes true, or never true in the past 12 months?	Often true*	45	40·54	32	32·99
	Sometimes true	35	31·53	33	34·02
	Never true	31	27·93	32	32·99	0·513
3. You and other household members couldn’t afford to eat balanced meals. In the past 12 months was that often true, sometimes true, or never true?	Often true*	43	38·39	26	26·80
	Sometimes true	40	35·71	39	40·21
	Never true	29	25·89	32	32·99	0·193
4. In the past 12 months, did you or other adults in your household ever cut the size of your meals or skip meals because there wasn’t enough money for food?	Yes*	64	78·05	54	72·97
	No	18	21·95	20	27·03	0·461
5. How often did this happen? (Referring to item 4)	Almost every month*	39	48·75	30	40·54
	Some months but not every month	19	23·75	23	31·08
	Only 1 or 2 months	4	5·00	1	1·35
	Not applicable (‘No’ to item 4)	18	22·50	20	27·03	0·378
6. In the past 12 months, did you ever eat less than you felt you should because there wasn’t enough money to buy food?	Yes*	68	79·07	48	65·75
	No	18	20·93	25	34·25	0·060
7. In the past 12 months, were you ever hungry but didn’t eat because you couldn’t afford enough food?	Yes*	69	80·23	52	69·33
	No	17	19·77	23	30·67	0·110
8. In the past 12 months, did you lose weight because you didn’t have enough money for food?	Yes*	60	71·43	42	56·76
	No	24	28·57	32	43·24	0·054
9. In the past 12 months, did you or other adults in your household ever not eat for a whole day because there wasn’t enough money for food?	Yes*	49	60·49	37	59·68
	No	32	39·51	25	40·32	0·921
10. How often did this happen? (Referring to item 9)	Almost every month*	22	27·85	16	25·81
	Some months but not every month	19	24·05	17	27·42
	Only 1 or 2 months	6	7·59	4	6·45
	Not applicable (‘No’ to item 9)	32	40·51	25	40·32	0·965
Food security status	Food insecure	86	74·14	69	69·70
	Food secure	30	25·86	30	30·30	0·469

^*An affirmative response on the HFSSM.

Table 2.

Baseline descriptive characteristics of 116 Dr. Peter Centre (DPC) clients in Vancouver, Canada (February 2014–March 2016)

Variable	Total n 116
	n	%
cART adherence in the past 12 months (outcome)
<95 %	38	32·76
≥95 %	78	67·24
Food security (exposure)
Food secure	30	25·86
Food insecure	86	74·14
Potential confounders (categorical variables)
Often have a drink containing alcohol
Never	46	39·66
Sometimes	70	60·34
Illicit drug use in the past 6 months (excluding marijuana)
No	54	46·55
Yes	62	53·45
Biological sex at birth
Male	101	87·07
Female	15	12·93
Homeless in the past 12 months
No	89	76·72
Yes	27	23·28
Self-reported anxiety and/or depression
Not anxious or depressed	29	25·00
Anxious or depressed	87	75·00
Prison or jail ever
No	57	49·14
Yes	59	50·86
Ever diagnosed with hepatitis C
No	35	30·17
Yes	81	69·83
Food assistance for most recent regimen
Taken without food/with or without food	26	22·41
Taken with food	81	69·83
With DPC less than 1 year at baseline
No	50	43·10
Yes	66	56·90
Currently working for pay
No	107	92·24
Yes	9	7·76
Current smoking status
No	35	30·17
Yes	81	69·83
Currently living with someone
Alone	100	86·21
With others	16	13·79
Indigenous ancestry
No	75	64·66
Yes	41	35·34
Highest level of education
Some post-secondary and above	46	39·66
High school and below	70	60·34
Issues with performing usual activities due to health state
No issues	67	57·76
Some issues/unable	49	42·24
Three antiretrovirals in current regimen
Yes	108	93·10
No	8	6·90
	Median	Q1–Q3
Potential confounders (continuous variables)
Age at interview date	46	39–52
Household monthly income before taxes ($CAN)	1100	1064·5–1151
Cumulative months on cART at visit	47	21–97

cART, combination antiretroviral therapy; Q1, quartile 1; Q3, quartile 3.

In the unadjusted analysis (Table 3), experiences of FI were associated with suboptimal cART adherence (unadjusted OR = 0·44, 95 % CI 0·24, 0·82). Furthermore, after adjustment for potential confounding factors, FI remained associated with suboptimal adherence (aOR = 0·47, 95 % CI 0·24, 0·93). In other words, those who experienced FI were approximately half as likely to be adherent to cART (≥95 %) compared with those who were food secure.

Table 3.

Univariable and multivariable analyses of the relationship between food insecurity and ≥95 % combination antiretroviral therapy (cART) adherence among clients of the Dr. Peter Centre (DPC) in Vancouver, Canada (February 2014–March 2016)

					Unadjusted logistic regression models		Adjusted logistic regression models
	Total n 116				(estimated by generalized estimating equations)
	<95 % cART adherent (n 77)		≥95 % cART adherent (n 138)		Outcome: ≥95 % v. <95 % cART adherent (total observations = 215)
Variable	n	%	n	%	Unadjusted OR	95 % CI	Adjusted OR	95 % CI
Food security (exposure)
Food secure	13	16·88	47	34·06	Ref.	–	Ref.	–
Food insecure	64	83·12	91	65·94	0·44	0·24, 0·82	0·47	0·24, 0·93
Confounders (categorical variables)
Often have a drink containing alcohol
Never	32	41·56	56	40·48	Ref.	–
Sometimes	45	58·44	82	59·42	0·99	0·53, 1·85	Not selected*
Illicit drug use in the past 6 months (excluding marijuana)
No	30	38·96	81	58·70	Ref.	–	Ref.	–
Yes	47	61·04	57	41·30	0·51	0·28, 0·92	0·59	0·32, 1·09
Biological sex at birth
Male	68	88·31	118	85·51	Ref.	–
Female	9	11·69	20	14·49	1·31	0·47, 3·63	Not selected
Homeless in the past 12 months
No	61	79·22	114	82·61	Ref.	–
Yes	16	20·78	24	17·39	0·88	0·43, 1·80	Not selected
Self-reported anxiety and/or depression
Not anxious or depressed	18	23·38	44	31·88	Ref.	–	Ref.	–
Anxious or depressed	59	76·62	94	68·12	0·64	0·32, 1·29	0·77	0·35, 1·70
Prison or jail ever
No	35	45·45	70	50·72	Ref.	–
Yes	42	54·55	68	49·28	0·84	0·45, 1·59	Not selected
Ever diagnosed with hepatitis C
No	18	23·38	46	33·33	Ref.	–	Ref.	–
Yes	59	76·62	92	66·67	0·63	0·30, 1·33	0·56	0·25, 1·26
Food assistance for most recent regimen
Taken without food/with or without food	13	16·88	37	26·81	Ref.	–
Taken with food	64	83·12	101	73·19	0·63	0·32, 1·21	Not selected
With DPC less than 1 year at baseline
No	34	44·16	62	44·93	Ref.	–
Yes	43	55·84	76	55·07	0·97	0·52, 1·84	Not selected
Currently working for pay
No	71	92·21	124	89·86	Ref.	–
Yes	6	7·79	14	10·14	0·91	0·33, 2·49	Not selected
Current smoking status
No	19	24·68	49	35·51	Ref.	–
Yes	58	75·32	89	64·49	0·68	0·35, 1·34	Not selected
Currently living with someone
Alone	71	92·21	114	82·61	Ref.	–	Ref.
With others	6	7·79	24	17·39	2·55	1·09, 5·94	3·32	1·47, 7·50
Indigenous ancestry
No	46	59·74	93	67·39	Ref.	–
Yes	31	40·26	45	32·61	0·75	0·40, 1·42	Not selected
Highest level of education
Some post-secondary and above	30	38·96	56	40·58	Ref.	–
High school and below	47	61·04	82	59·42	0·98	0·54, 1·78	Not selected
Issues with performing usual activities due to health state
No issues	45	58·44	81	58·70	Ref.	–
Some issues/unable	32	41·56	57	41·30	0·87	0·49, 1·56	Not selected
Three antiretrovirals in current regimen
Yes	74	96·10	125	90·58	Ref.	–
No	3	3·90	13	9·42	2·14	0·61, 7·57	Not selected

Ref., reference category; Q1, quartile 1; Q3, quartile 3.

^*Not selected after change-in-estimate approach: if the coefficient for food insecurity changed by less than 5 % after the omission of a given confounder, the variable was not adjusted for in the final model.

Discussion

The present study examined the relationship between FI and cART adherence among a cohort of PLHIV who were clients of the DPC in Vancouver, Canada. Nearly three-quarters of DPC participants reported experiencing FI in the past 12 months. The high prevalence of FI among DPC clients was similar to that documented in other Canadian studies of PLHIV^(7,8,40,41). Two studies conducted in BC (2011 and 2016) found the percentage of food-insecure PLHIV to be almost identical to the 74 % of participants identified in the present study^(8,40). Also in line with other studies, individuals who were food insecure were approximately half as likely to be adherent to cART after adjusting for potential clinical, social and demographic confounders of the FI–cART adherence relationship^(9,42).

The present study’s results must be interpreted in the context of previous literature detailing how interventions that focus on food provision (e.g. food banks, community gardens) do not necessarily alleviate FI over an extended period of time, particularly in resource-rich settings^(23,43–45). While food provision can provide other benefits (e.g. the mitigation of hunger⁽²⁴⁾ (a physical sensation experienced by those with severe FI)⁽⁴⁶⁾, entry points to health-care services⁽²⁵⁾, promotion of social interactions^(41,47) and support for development of daily routines^(25,45)), the root driver of FI in resource-rich settings is inadequate financial resources^(43,48–50). Our study further demonstrates this as FI remains prevalent among DPC clients despite the provision of food. In addition, there remains a relationship between this prevalent experience and suboptimal cART adherence in this integrated care programme.

While our study cannot evaluate any of the potential mechanisms by which FI leads to suboptimal cART adherence, our work provides impetus for additional research to better understand how to attenuate the relationship between these two factors in this setting and in other similar environments. For example, FI has a known association with depression^(51,52) and dependence on drugs and alcohol⁽⁵³⁾, all of which are linked with suboptimal cART adherence^(39,54–56). FI, along with other needs (e.g. housing, transportation) that stem from limited financial resources, may also impact cART adherence when meeting these needs interferes with medication access or medical appointments^(19,57,58). Analyses that explicate how these pathways may be leveraged to attenuate the impact of FI on cART adherence among structurally vulnerable PLHIV are necessary.

The findings of the present study also point to a need to consider the broader implications of food provision within integrated care models, beyond the scope of mitigating FI. In particular, the food programme at the DPC can be conceptualized within the organization’s broader harm reduction mandate, which aims to improve health and reduce health- and drug-related harms^(21,41,45). For example, the food programme at the DPC has been shown to be an integral element of the Centre and a primary access point for individuals interacting with the space^(25,45). Overall, the benefits of integrated care models that include food provision must consider how programming may positively impact clients through a harm reduction approach, even if experiences, such as FI, remain prevalent.

The DPC offers a unique environment in which to study FI and adherence to cART. However, our study warrants consideration of some potential limitations. Participants of the present study were not randomly selected and are thus not representative of the general population of PLHIV in BC. In fact, because the admission requirements for the DPC necessitate a deteriorating health status⁽²¹⁾, the sample in the present study may over-represent individuals with complex health needs. In addition, while the HFSSM is a validated measurement tool for FI, fluctuations in FI within a 12-month period is an inherent limitation to the use of the HFSSM⁽⁴⁶⁾. Another limitation of the study is that we are unable to stratify our analysis or adjust our regression models by whether a participant in fact received meals at the DPC. Therefore, we cannot directly attribute the impact of this particular service on the relationship between FI and adherence. However, previous work conducted among thirty DPC clients who used illicit drugs showed that 100 % (n 30) of clients surveyed accessed the DPC food programme for some of their meals, with 80 % (n 24) using the programme daily and the other 20 % (n 6) using the programme weekly (C Miewald, unpublished results). Our findings are contextualized based on this understanding, as well as other published literature including DPC clients^(25,45).

Conclusion

In conclusion, the present study documented a high prevalence of FI among DPC clients in Vancouver, Canada. As such, while food provision may have benefits related to harm reduction, there remains a relationship between this prevalent experience and cART adherence in this integrated care programme. Future studies that elucidate strategies to mitigate FI among PLHIV in this setting and in other similar environments are necessary.