Authors, year / populationa | Results — drug use, for/between specific populations |
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Older adults, seniors | |
Adams, Soumerai, Ross-Degnan, 2001 [15]; – US Medicare population (65+ years) | In the US Medicare population, drug coverage was associated with greater use of all drugs and clinically essential medications. Magnitude, seniors: reductions in drug use ranged between 21 and 46% depending on the drug class and condition of patients. Magnitude, seniors vs. non-seniors: unclear. |
Rice, Matsuoka, 2004 [18]; – Seniors | Among seniors, cost-sharing (not necessarily for drugs) was found to reduce the appropriate use of prescription drugs (medications that were thought to improve health status). Magnitude, seniors: unclear. Magnitude, seniors vs. non-seniors: unclear. |
Maio, Pizzi, Roumm, 2005 [20]; – Seniors | There was mixed evidence that prescription cost-sharing mechanisms (copayment, coinsurance, and deductible) reduced seniors’ drug use. There was some evidence that for low-income populations, even small copayments, may have led them to reduce their use of effective medications. Magnitude, seniors: unclear. Magnitude, seniors vs. non-seniors: unclear. |
Briesacher, Gurwitz, Soumerai, 2007 [21]; – General population | There was strong evidence that among medicare beneficiaries, drug coverage decreased the risk of cost-related medication nonadherence; strong evidence that among medicare beneficiaries and adults 50+, higher cost-sharing increased the risk of cost-related medication nonadherence. Magnitude, older adults, seniors: unclear. Magnitude, older adults, seniors: vs. non-older adults, non-seniors: unclear. |
Gemmil, Thomson, Mossialos, 2008 [24] – General population | Older people were not found to be more sensitive to price than the general population. Magnitude, older adults: a 10% increase in price led to changes in use for older people ranging from a 5.6% reduction to a 0.9% increase based on non-aggregate data, and one study using aggregate data found a reduction of 5.1%. Magnitude, older adults vs. non-older adults: among the general population, price elasticity estimates suggested that a 10% increase in price led to a 0.2 to 4.6% decrease in use based on non-aggregate data and a 0.9 to 8.0% decrease in use based on aggregate data. |
Holst, 2010 [27]; – General population | Older people responded especially sensitively to cost-sharing. Magnitude, older adults: unclear. Magnitude, older adults vs. non-older adults: unclear. |
Polinski, Kilabuk, et al., 2010 [28]; – US Medicare population (65+ years) | The inception of Medicare Part D was associated with a consistent overall increase in drug use. There was little variation in effect estimates between studies evaluating the effect of Part D implementation. Across all studies, entry of Part D beneficiaries into the coverage gap was associated with reduced drug use. Magnitude, seniors: the inception of Part D was associated with a 6 to 13% increase in drug use. Changes in use varied according to drug, disease, and population studied. There was little indication that Part D selectively led to greater use of essential, underused drugs than of overused medications. Across all studies, entry of Part D beneficiaries into the coverage gap was associated with 9 to 16% less drug use. Patients who entered the coverage gap were 5 to 11% more likely to report discontinuing, switching, or failing to initiate a medication than were patients who did not enter the coverage gap. Use of generic drugs increased 20% during the coverage gap. Magnitude, seniors vs. non-seniors: unclear. |
Swartz, 2010 [29]; – General population | Cost-sharing reduced use of essential drugs in people with chronic conditions and the elderly. Studies that looked at the Medicare doughnut hole found that elderly reduced drug use when they had to pay full price. Magnitude, elderly: one study in the elderly found cost-sharing reduced essential drugs by 9% for essential drugs and 15% for nonessential drugs. Magnitude, elderly vs non-elderly: unclear. |
Baicker, Goldman, 2011 [30]; – General population | One study that examined Medicare Part D found that providing insurance to the elderly led to increased prescription drug use. Magnitude, seniors: providing insurance to the elderly led to a 13% increase in prescription drug use. Further interpretation not provided Magnitude, seniors vs. non-seniors: unclear. |
Polinski, Donohue, et al., 2011 [31]; – US Medicare population (65+ years) | In the period after Medicare Part D implementation there was an increase in the use of essential medicines especially in beneficiaries who had been previously uninsured, and of nonessential medicines. During the transition period, dually eligible beneficiaries’ drug use remained largely unchanged. In the coverage gap, when cost-sharing increased, the use of essential and overused medications declined. Magnitude, seniors: unclear Magnitude, seniors vs. non-seniors: unclear. |
Pimentel, Lapane, Briesacher, 2013 [35]; – US Medicare population (65+ years) in long-term care | Findings of prescription drug utilization were mixed. Prescription drug benefit was associated with decreased use of drugs that carry safety concerns, but overall drug utilization may have been unaffected. A shift in drug utilization within drug classes was seen (i.e., from non-covered to covered drugs and utilization of new drugs to treat side effects). Magnitude, seniors: unclear. Magnitude, seniors vs. non-seniors: unclear. |
Park, Martin, 2017 [7]; – US Medicare population (65+ years) | Studies consistently found that Medicare Part D increased drug utilization across numerous outcomes, including medication persistence, number of days with possession of at least 1 drug within a class, annual prescription fills per person, drug access, and cost-related behaviour changes such as medication cessation, applying to pharmaceutical assistance programs, and receiving free prescription samples. Similarly, Medicare Part D coverage gaps negatively impacted drug utilization. The coverage gap prompted some substitution of generic for brand-name drugs. Magnitude, seniors: the strongest effect sizes were for medication use and increases were highest among beneficiaries receiving low-income subsidies. Magnitude, seniors vs. non-seniors: unclear. |
Ofori-Asenso, Jakhu et al., 2018 [47]; – 65+ years statins users | Higher copayment/cost (not necessarily drug cost-sharing) increased the likelihood of nonadherence and of discontinuation. Magnitude, seniors: the association between higher copayment and nonadherence and discontinuation was positive (OR 1.4, 95%CI 1.3, 1.5; OR 1.6, 95%CI 1.5, 1.7). Further interpretation not provided. Magnitude, seniors vs. non-seniors: unclear. |
Mishuk, Fasina, Qian, 2019 [51]; – Individuals affected by US federal and state generic drug policies | Existing evidence evaluating Medicare Part D suggested decreased prescription spending for beneficiaries and increased use of generics. Policies lowering cost-sharing were associated with increased patient’s medication use and adherence, but the impact varied by therapeutic classes while government insurance plans with higher cost-sharing were associated with reduced generic utilization. Evidence suggested that lower cost-sharing increased generic drug use which further enhanced medication adherence. Magnitude, seniors: unclear. Magnitude, seniors vs. non-seniors: unclear. |
Socioeconomic status, chronically ill | |
Lexchin, Grootendorst, 2004 [17]; – The poor and chronically ill | Cost-sharing through the use of copayments or deductibles decreased the use of prescription drugs by the poor and the chronically ill. Magnitude, poor/chronically ill: drug price elasticities among vulnerable groups — those with low income and/or chronic illnesses — generally ranged from −0.34 to − 0.50. Some evidence that cost-sharing led to patients foregoing essential medications. Magnitude, poor/chronically ill: vs. non-poor/chronically ill: unclear. |
Goldman, Joyce, Zheng, 2007 [23]; – General population | – Low-income Although studies suggested that low-income beneficiaries reduced drug use with higher copayments, there was little evidence that individuals of lower-income were more sensitive to increased cost-sharing than the general population. Magnitude, low-income: same as the general population. Magnitude, low-income vs. non-low-income: same as the general population. – Chronically ill The evidence suggested that even chronically ill patients were responsive to cost-sharing. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs. non-chronically ill: unclear. |
Gemmil, Thomson, Mossialos, 2008 [24]; – General population | Poorer people were not found to be more sensitive to price than the general population. Magnitude, poor: among the poor, a 10% increase in price led to reductions in use ranged from 0.3 to 2.0% based on non-aggregate data and 0.5 to 4.0% based on aggregate data. Magnitude, poor vs. non-poor: among the general population, a 10% increase in price led to a 0.2 to 4.6% decrease in use based on non-aggregate data and a 0.9 to 8.0% decrease in use based on aggregate data. |
Remler, Greene, 2009 [25]; – General population | – Low-income Evidence has not consistently shown a relationship between income and cost-sharing effects; the findings were mixed and not conclusive, and the work was limited by the relatively homogenous populations and proxy measures of income. Magnitude, low-income: unclear. Magnitude, low-income vs. mid-, high-income: unclear. – Chronically ill Only a few studies compared the impact of cost-sharing on different health status groups; pharmaceutical cost-sharing among those with chronic disease sometimes reduced the use of valuable drugs; several studies conducted on chronically ill populations (including those with rheumatoid arthritis, heart failure, diabetes, schizophrenia, and lipid disorders) found unambiguous reductions in the use of drugs regarded as important for maintaining the health of the chronically ill. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs. non-chronically ill: unclear. |
Holst, 2010 [27]; – General population | – Low-income Some evidence that lower-income individuals were sensitive to increased cost-sharing. Magnitude, subgroup: unclear. Magnitude, low-income vs. mid-, high-income: unclear. – Chronically ill Cost-induced nonadherence to medical recommendations was observed more often among people who needed treatment than among healthy citizens. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs. non-chronically ill: unclear. |
Swartz, 2010 [29]; – General population | One study that examined changes in prescription drug copayments imposed on privately insured people indicated that for each medication class examined, individuals living in high-income areas were consistently more likely to continue taking their medications than people in low-income areas after copayments increased. Magnitude, poor: unclear. Magnitude, poor vs non-poor: unclear. |
Lemstra, Blackburn et al., 2012 [33]; – Statin users | Statin users required to make a copayment were more likely than others to be nonadherent. Magnitude, statin users: among 6 studies with a total sample size of 884,643, patients required to make a copayment when their statin medications were dispensed were 28% more likely than others to be nonadherent (rate ratio 1.3; 95%CI 1.1, 1.5). Magnitude, statin users vs. non-statin users: unclear. |
Maimaris, Paty, et al., 2013 [34]; – Individuals with hypertension | Health insurance and lower cost-sharing were associated with hypertension treatment (defined as the use of at least one antihypertensive medication in an individual with known hypertension) and antihypertensive medication adherence. Magnitude, individuals with hypertension: unclear. Magnitude, individuals with hypertension vs. individuals without hypertension: unclear. |
Kiil, Houlberg, 2014 [37]; – General population | The majority of studies found that copayments led to a larger reduction in the use of prescription medicine for vulnerable population groups than for the non-vulnerable general population. Magnitude, vulnerable population: unclear. Magnitude, vulnerable population vs. non-vulnerable general population: unclear. |
Mann, Barnieh, et al., 2014 [38]; – Individuals with cardiovascular-related chronic disease | The addition of drug insurance for those without previous drug insurance appear to have consistently increased adherence to medications. In general, studies evaluating drug insurance cost-sharing strategies had conflicting results with some studies showing significant differences in some outcomes while other studies demonstrated no discernible difference in outcomes. The use of deductibles (up to $350 per year) did not appear to have a significant impact on medication adherence. The impact of a maximum out-of-pocket limits was uncertain. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs. non-chronically ill: unclear. |
Banerjee, Khandelwal, et al., 2016 [42]; – Individuals with cardiovascular diseases | Reduced copayments and full prescription coverage were associated with increased adherence and persistence. Magnitude, individuals with cardiovascular diseases: two retrospective cohort studies investigated the impact of copayments on adherence; 1) among 4105 patients with acute myocardial infarction in Austria, those with waived copayments had higher persistence at 120 days for drug therapy with aspirin, statins, angiotensin-converting enzyme inhibitors (ACEI) or angiotensin-receptor blockers (ARB) than those with copayments (OR 1.4, 95%CI 1.1, 1.7), but β blocker (OR 1.1, 95%CI 0.9, 1.4) or statin use (OR 1.1, 95%CI 0.9, 1.3) did not significantly differ between these groups; 2) a US study of coronary heart disease patients found that compared with copayments <US$10, copayments ≥US$20 were associated with lower persistence at 1 year for statins (OR 0.42; 95%CI 0.36 to 0.49). A US-based RCT included 5855 individuals post-myocardial infarction, randomized to full or usual prescription coverage. Full adherence was higher with full prescription coverage for all medication classes (OR 1.4, 1.2, 1.7). Increased adherence to all three medications for the patient subgroup undergoing coronary artery bypass graft was found, post hoc (OR 1.7, 95% CI 1.04 to 2.7). Magnitude, individuals with cardiovascular diseases vs. individuals without cardiovascular diseases: unclear. |
Doshi, Li et al., 2016 [43]; – Individuals using specialty drugs | – Prescription abandonment (prescription submitted and approved by the insurer but not obtained by the patient): all studies (n = 3) reported a strong association of higher cost-sharing with abandonment (vs initiation) of specialty drug prescriptions, for all indications examined. Magnitude, individuals using specialty drugs: unclear. – Initiation (first time use of specialty drug within a study period): all studies (n = 8) examining initiation in patients with rheumatoid arthritis and multiple sclerosis reported a negative association with higher cost-sharing. Initiation of specialty drugs for cancer was largely reported to be insensitive to cost-sharing in the 3 studies examining this outcome. Magnitude, individuals using specialty drugs: the demand elasticity ranged from − 0.03 to − 0.33 for patients with rheumatoid arthritis or multiple sclerosis. – Adherence: evidence on relationship between cost-sharing and adherence was mixed. The majority of studies reported a statistically significant increase in discontinuation associated with increased cost-sharing. Magnitude, individuals using specialty drugs: unclear. – Discontinuation/persistence (having a continuous gap of time between prescription fills): 6 of the 7 studies reported a statistically significant increase in discontinuation (or decrease in persistence) associated with increased cost-sharing for at least 1 of the indications examined. Magnitude, individuals using specialty drugs: the magnitude of the effects appeared small. |
Powell, Saloner, Sabik, 2016 [44]; – Medicaid beneficiaries | Increasing copayments resulted in decreased utilization of drugs and higher rates of non-adherence. However, the magnitude of these associations varied across subgroups. In patients with high need for prescription drugs, studies found that increased copayments resulted in decreased adherence. This was found in Medicaid patients with schizophrenia and privately insured adults with diabetes and congestive heart failure who were living in lowest median income areas. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs non-chronically-ill: unclear. Magnitude, poor: unclear. Magnitude, poor vs non-poor: unclear. |
Gourzoulidis, Kourlaba, et al., 2017 [45]; – Individuals with heart failure or diabetes mellitus | 7 of 8 studies evaluating the relationship between drug copayment and medication adherence in diabetes mellitus population and 1 of 3 in heart failure population, found a statistically significant inverse association between increases in copayments and medication adherence. Magnitude, individuals with heart failure or diabetes mellitus: unclear. Magnitude, individuals with heart failure or diabetes mellitus vs. individuals without heart failure or diabetes mellitus: unclear. |
Gupta, McColl et al., 2018 [46]; – Canadians | Three studies including people with cardiovascular conditions found that those spending ≥5% costs of medications out of their pocket were more likely to report cost-related non-adherence than those spending < 5%. Magnitude, chronically ill: unclear. Magnitude, chronically ill vs. non-chronically ill: unclear. |
Schneider, Gaedke et al., 2018 [48]; – Individuals with chronic cardiovascular diseases | Among individuals with chronic cardiovascular diseases, access to insurance or other programs that assisted with medication costs was a protective factor for nonadherence. Magnitude, chronically ill: insurance or programs that assisted with medication cost was correlated with a 24% decrease in the risk of nonadherence (OR 0.76; 95%CI 0.60, 0.95). Magnitude, chronically ill vs. non-chronically ill: unclear. |
Cheen, Tan et al., 2019 [49]; – Individuals with any of six common chronic diseases. | On the whole, among individuals with chronic diseases (asthma, chronic obstructive pulmonary disease, depression, diabetes mellitus, hyperlipidaemia, hypertension and osteoporosis), higher copayments were associated with primary medication nonadherence. Magnitude, chronically ill: a high copayment amount had the strongest association with primary medication nonadherence, with ORs ranging from 1.01 to 33 (compared to lower copayments); Magnitude, chronically ill vs. non-chronically ill: unclear. |