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Table 1 Study characteristics and results

From: Cost-related medication nonadherence in Canada: a systematic review of prevalence, predictors, and clinical impact

Study ID, design Demographics Definition of CRNA Prevalence of CRNA Predictors of CRNAa Impact on clinical outcomes
Brand 1977 [35]
Survey with in-person interviews over a 3-month period, year unspecified
N = 225 patients discharged from hospital in Halifax, NS (mean age 57.0) Not complying with ≥ 1 physician order(s) due to cost of drugs 13.8% “Cost of drugs” (p < 0.001) N/A
Kennedy 2006 [36]
2002–2003 Joint Canada-US Survey of Health
N = 3505 Canadian adults ≥ 18 years Failure to obtain a prescribed medication due to cost 5.1% No Canada-specific data N/A
Hirth 2008 [37]
2002–2004 DOPPS patient questionnaires
N = 503 Canadian adult hemodialysis patients from 20 facilities (mean age 62.1, SD 14.7) Not purchasing medication due to cost 12.9% Out-of-pocket spending burden (R2 = 0.44) N/A
Kennedy 2009 [38]
2007 IHP phone survey
N = 2980 Canadian adults ≥ 18 years Not filling a prescription or skipping doses of medication due to cost during the previous 12 months 8.0% Younger (< 65 years), multiple chronic conditions, lower household income, each p < 0.01 (OR not reported); Quebec (compulsory coverage) compared to Ontario (OR = 0.5, 95% CI 0.3–0.8) N/A
Kemp 2010 [39]
2007 IHP phone survey
N = 2183 Canadian adults ≥ 18 years (median age 50, SE 0.3) Not filling a prescription or skipping doses of medication due to cost during the previous 12 months 8.0% Younger age RR = 3.9 (95% CI 2.2–6.9); income below average RR = 3.1 (95% CI 2.1–4.7); high out-of-pocket prescription costs (RR = 4.6 (95% CI 3.8–6.7); first nations RR = 2.1 (95% CI 1.4–3.2); self-reported poor health status RR = 1.5 (95% CI 1.2–2.0); not feeling involved in treatment decisions RR = 1.3 (95% CI 1.1–1.4) N/A
Law 2012 [40]
2007 CCHS phone survey
N = 5732 community-dwelling Canadians ≥ 12 years who received a prescription in the previous year Altering a prescription to make it last longer or not filling a new prescription or renewing an ongoing prescription, due to cost Canadian sample, 9.6% (95% CI 8.4–10.7%); QB, 7.2% (4.5–9.8); ON, 9.1% (7.2–11.0%); BC, 17.0% (12.6–21.4%) Younger age (OR = 4.70, 95% CI 2.91–7.60); low household income (OR = 3.29, 95% CI 2.03–5.33); lack of insurance coverage for drugs (OR = 4.52, 95% CI 3.29–6.20); several chronic health conditions (OR = 1.61, 95% CI 1.07–2.43); fair or poor self-assessed health status (OR = 2.64, 95% CI 1.77–3.94); residing in BC (compared to Ontario) (OR = 2.56, 95% CI 1.49–4.42) N/A
Zheng 2012 [41]
Cross-sectional survey with in-person interviews between March 10 and April 19, 2011
N = 60 adult patients attending a general internal medicine rapid assessment outpatient clinic in Hamilton, ON (mean age 60.3, SD 14.3) Left prescriptions unfilled, delayed filling prescriptions, took prescriptions with reduced frequency or lowered dosages in the previous year because of the cost 15.0% No drug insurance (OR = 20.7, 95% CI 1.46–292.75); high out-of-pocket expenses (OR = 42.52, 95% CI 2.02–894.03) N/A
Hunter 2015 [42]
HHiT study in-person interviews between January and December 2009
N = 716 homeless or vulnerably housed single adults in Vancouver, Toronto, and Ottawa and prescribed ≥ 1 current medication Not actually taking a current medication prescribed by a doctor as “the medication is too expensive” 3.6% N/A N/A
Hennessy 2016 [2]
BCPCHC survey between February 2011 and March 2012
N = 1849 ≥ 40 year from BC, AB, SK, or MB who reported having heart disease, stroke, diabetes, or hypertension (mean age 65.1, 95% CI 64.3–65.9) For the previous 12 months, due to cost, either (a) not getting necessary prescription medication or (b) stopping one or more prescribed drug for a week or more 4.1% (95% CI 2.6–6.3%) Out-of-pocket spending greater than 5% of household income (prevalence RR = 2.6; 95% CI 1.0–6.4) N/A
Lee 2017 [43]
2014 IHP phone survey
N = 4690 community-dwelling Canadians ≥ 55 years Not filling a prescription or skipping doses within the last 12 months because of out-of-pocket costs 8.3% QC (compared to ON) (adjusted OR = 0.49, 95% CI 0.29–0.82); younger age (compared to ≥ 65 years): 55–64 years (OR = 3.13, 95% CI 2.27–5.40); poor health status (OR = 1.75, 95% CI 1.12–2.38); low income (OR = 3.59, 95% CI 2.32–5.55); lack of private insurance (OR = 2.33, 95% CI 1.56–3.10) N/A
Morgan 2017 [3]
2014 IHP phone survey
N = 4696 community-dwelling Canadians ≥ 55 years Not filling a prescription or skipped doses within the last 12 months because of out-of-pocket costs 8.3% Canadians (compared to the UK) (adjusted OR = 2.25, 95% CI 1.08–4.69); lower income (compared to UK) (OR = 1.23, 95% CI 0.64–2.40) N/A
Sarnak 2017 [44]
OECD data, 2016 IHP phone survey and other sources
N = 4547 Canadian adults ≥ 18 years Not filling/collecting a prescription for medicine or skipped doses because of cost in the past 12 months Overall: 10.2%; 0 chronic diseases 5.0% vs. 1 chronic disease 12.0% vs. 2+ chronic diseases 16.0% N/A N/A
Soril 2017 [45]
2004-14 IHP phone surveys (selected years)
N = 25,740 Canadian adults ≥ 18 years Not filling a prescription because of costs in the previous 12 months Overall: range 7.1–8.2%; older/sicker adult cohort: range 6.5–19.8% N/A N/A
Law 2018 [46]
2016 CCHS phone survey
N = 28,091 community-dwelling Canadians ≥ 12 years Skipping or reducing dosages, or delaying refill prescriptions or not filling prescriptions at all to reduce drug costs 5.5% (95% CI 5.1–6.0%) Younger adult (p < 0.001); out-of-pocket prescription drug spending (p < 0.001); lack of drug insurance (p < 0.001); lower income (p < 0.001); poorer health status (p < 0.001) N/A
Laba 2018 [47]
2016 CCHS phone survey
N = 8420 community-dwelling Canadians ≥ 12 years old with ≥ 2 chronic conditions Skipping or reducing dosages, delaying refill prescriptions, or not filling prescriptions at all to reduce drug costs 10.2% (95% CI 8.6–11.9%); 15.2% (95% CI 11.6–18.8) for respiratory and 16.6% (95% CI 13.2–9.9%) for mental health disorders Age between 19 and 44 years (OR 2.74, 95%CI 1.76, 4.26); out-of-pocket spending on prescription medicines > CAD500 OR 2.56, 95% CI 1.49, 4.40; lack of drug insurance (OR 3.26, 95% CI 2.12, 4.80); fair to poor health status (OR 3.42, 95% CI 1.46, 8.02); residing in certain provinces, e.g., BC (OR 4.20, 95% CI 2.55, 6.91) N/A
Men 2019 [48]
2016 CCHS phone survey
N = 11,172 community-dwelling Canadians with a prescription within the previous year and answering a food security questionnaire Skipping or reducing dosages, delaying refill prescriptions, or not filling prescriptions at all to reduce drug costs 8.3% Household food insecurity adjusted for sociodemographic factors, associated with CRN—RR 1.82 (95% CI 1.00 to 3.31), 3.83 (95% CI 2.44 to 6.03), and 5.05 (95% CI 3.27 to 7.81) for marginally, moderately, and severely food-insecure households, respectively, compared to those with no food insecurity N/A
Monagle 2018 [49]
Phone survey of one anticoagulant clinic
N = 110 adult patients newly started on oral anticoagulants in Hamilton, ON Leaving a prescription unfilled or delaying filling a prescription, or taking less of a medication, due to cost Warfarin users were more likely to report CRN than NOAC users (40% vs. 13%, p = 0.02) N/A N/A
Yao 2018 [50]
Retrospective pre-post database study 2005–2009 pre- and post-Seniors’ Drug plan policy change (max. out-of-pocket $15 per prescription for patients ≥ 65 years) vs. concurrent control patients 40–64 years not affected by the policy
N = 188,109 observed patients in SK CRNA assumed if adherence post-policy improved compared pre-period and to unaffected control N/A Odds of optimal medication adherence: post-SDP (compared to pre-SDP) (OR = 1.08, 95% CI 1.04 to 1.11), but only where OOP costs > $15 per prescription, for prevalent users, for some medication classes. Not compared directly to concurrent control N/A
Dormuth 2006 [51]
Retrospective pre-post database study between June 1997 and 2004 with monthly time series pre- (full coverage) vs. post-policy (copayment)
N = 55,752 BC residents ≥ 65 years not in a nursing home, dispensed inhaled corticosteroids (ICS) in 2001 (mean age 75.5) CRNA assumed if the use of respiratory inhalers declined after policy increasing out-of-pocket expenses N/A Initiation of ICS for a new diagnosis of asthma or COPD compared to pre-policy reduced by 25% (95% CI 14–31%); discontinuation of ICS was increased 47% (40–55%) in the copayment group N/A
Schneeweiss 2007 [52]
Retrospective pre-post database study 2000–2004 with repeated measures design, monthly adherence measurement pre- (full coverage) vs. post-policy (copayment)
N = 41,561 seniors in BC who were new users of statin drugs CRNA assumed if use of statins declined after policy increasing out-of-pocket expenses N/A Paying 100% out-of-pocket (compared to pre-policy) (OR = 1.94, 95% CI 1.82–2.08); patients post-myocardial infarction or post-revascularization (higher risk) (OR = 0.63, 95% CI 0.59–0.68) N/A
Schneeweiss 2007 [53]
Retrospective pre-post database study 2000–2004 with repeated measures design, monthly adherence measurement pre- (full coverage) vs. post-policy (copayment)
N = 13,193 seniors from BC who were new users of β-blockers CRNA assumed if the use of beta-blockers declined after policy increasing out-of-pocket expenses N/A Post-policy cohort (compared to pre-policy) associated with a 1.3% decline in adherence (95% CI 2.5–0.04) N/A
Goldsmith 2017 [54]
Qualitative study with semi-structured interviews of CRNA experience from patients’ perspective 2014–2015
N = 35 adults in BC and ON who reported CRNA Patient self-report of skipping doses, splitting pills, or not filling their prescriptions due to out-of-pocket costs N/A Type of insurance; individual’s overall financial flexibility; the burden of drug cost on the individual’s budget; perceived importance of the drug N/A
Gupta 2019 [55]
Qualitative study with semi-structured interviews of strategies used to deal with cost burden
N = 12 adult Canadians with spinal cord injuries who reported CRNA N/A N/A Out-of-pocket cost of medication; perceived importance of the drug; lack of drug insurance; competing financial needs, e.g., food, housing; inability to discuss with physicians N/A
Tamblyn 2001 [56]
Retrospective database study with interrupted monthly time series 1993–1997 pre (full coverage for welfare and low-income seniors; $2 copayment for all other seniors) vs. post-policy (25% coinsurance and deductible)
N = 70,801 elderly and 25,820 welfare recipients using “essential drugs” in QC CRNA assumed if post-policy decrease in the use of essential drugs N/A Increase in cost sharing associated with a decrease in essential drug use by elderly by 9.1% (95% CI 8.7–9.6) and by welfare recipients by 14.4% (95% CI 13.3–15.6%) Net increase in serious adverse events by 6.8 and 12.9 per 10,000/month; in ED visits by 14.2 and 54.2 per 10,000/month for elderly and for welfare recipients, respectively
Pilote 2002 [57]
Retrospective database study with time-series analysis 1994–1998 pre- (full coverage for welfare and low-income seniors and $2 copayment for all other seniors) vs. post-policy (25% coinsurance and deductible)
N = 22,066 patients ≥ 65 years admitted to a QC hospital for a first acute myocardial infarction and discharged alive CRNA assumed if the proportion of patients who filled at least one prescription during the year after discharge declined post-policy change N/A N/A as no change in adherence pre- vs. post-policy No differences in readmission for cardiac complications, mortality rate, or use of outpatient physician or ED services
Persaud 2019 [58, 59]
Randomized open-label trial 2016–2017 with free access including free delivery of prescribed essential medication, compared to usual care
N = 786 adults ≥ 18 years old in 9 primary care practices in ON who reported CRNA (mean age 51.7 years, 55.9% female) Self-reported not filling a prescription or making a prescription last longer because of the cost within the previous 12 months N/A No variation in adherence by income No difference in rates of hospitalization, serious adverse events, or deaths
  1. CRNA cost-related nonadherence, N/A data not available, BCPCHC barriers to care for people with chronic health conditions, DOPPS Dialysis Outcomes and Practice Patterns Study, HHiT health and housing in transition, IHP International Health Policy, CCHS Canadian Community Health Survey, OECD Organization for Economic Co-operation and Development, ICS inhaled corticosteroids, SDP Seniors’ Drug Plan, BC British Columbia, AB Alberta, SK Saskatchewan, MB Manitoba, ON Ontario, QC Quebec, NNT number needed to treat
  2. aUsing adjusted or multivariable analyses