Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2025 Sep 19.
Published in final edited form as: Addiction. 2022 Feb 1;117(6):1768–1777. doi: 10.1111/add.15795

A difference-in-difference approach to examining the impact of cannabis legalization on disparities in the use of cigarettes and cannabis in the United States, 2004–17

Andrea H Weinberger 1,2, Katarzyna Wyka 3, June H Kim 4, Rosanna Smart 5, Michael Mangold 6, Ellen Schanzer 1, Melody Wu 3,7, Renee D Goodwin 3,7
PMCID: PMC12445298  NIHMSID: NIHMS2109602  PMID: 34985165

Abstract

Aims:

To estimate the impact of recreational and medical cannabis laws (RCL, MCL) on the use of cannabis and cigarettes in the United States.

Design:

A difference-in-difference approach was applied to data from the 2004–17 National Survey on Drug Use and Health (NSDUH).

Setting:

United States.

Participants:

Nationally representative cross-sectional survey of Americans aged 12 years and older (combined analytical sample for 2004–17, n = 783 663).

Measurements:

Data on past-month use of (1) cigarettes and (2) cannabis were used to classify respondents into four groups: cigarette and cannabis co-use, cigarette-only use, cannabis-only use or no cigarette or cannabis use. State of residence was measured by self-report. MCL/RCL status came from state government websites.

Findings:

Difference-in-difference analyses suggest that MCL was associated with an increase in cigarette–cannabis co-use overall [adjusted odds ratio (aOR) = 1.09; 95% confidence interval (CI) = 1.02–1.16], with the greatest increases among those aged 50 years and above (aOR = 1.60; CI = 1.39–1.84), married (aOR = 1.19; CI = 1.07–1.31), non-Hispanic (NH) black (aOR = 1.14; CI = 1.02–1.07) and with a college degree or above (aOR = 1.15; CI = 1.06–1.24). MCL was associated with increases in cigarette-only use among those aged 50 years and above (aOR = 1.07; CI = 1.01–1.14) and NH black (aOR = 1.16; CI = 1.06–1.27) and increases in cannabis-only use among those aged 50 years and above (aOR = 1.24; CI = 1.07–1.44) and widowed/divorced/separated (aOR = 1.18; CI = 1.01–1.37). RCL was associated with an increase in cannabis-only use overall (aOR = 1.21; 95% CI = 1.09–1.34), a decline in cigarette-only use overall (aOR = 0.89; 95% CI = 0.81–0.97) and increases in co-use among those who were married (aOR = 1.24; CI = 1.02–1.50) and aged 50 years and above (aOR = 1.37; CI = 1.03–1.84).

Conclusions:

Recreational and medical cannabis legalization have had a varying impact on the use, and co-use, of cannabis and cigarettes in the United States.

Keywords: Cannabis, co-use, epidemiology, health policy, marijuana, NSDUH, smoking, tobacco

INTRODUCTION

Tobacco use remains the leading cause of premature death and disease in the United States [1] and globally [2,3]. While the prevalence of cigarette use has declined in the United States and other countries (e.g. in the United States from 42.0% in 1964 to 14.0% in 2019 [1,3-5]), cigarettes remain the most commonly used tobacco product by US adults [6]. Furthermore, socio-economic disparities in cigarette use are increasing [7-10].

In contrast to the decline in cigarette use, cannabis use is increasing broadly among the US adult population (e.g. from 6.2% in 2005 to 8.4% in 2014) [11-15]. As cannabis legalization is being adopted state-by-state across the United States cannabis use is becoming more widely socially accepted [16], and perceived risks of cannabis use are decreasing [13,17,18]. For instance, from 2002 to 2014, the percentage of US individuals aged 12 years and older who reported ‘great risk’ associated with cannabis decreased from 38.3 to 26.5%, while the percentage who reported ‘no risk’ associated with cannabis increased from 10.0 to 19.9% [14].

Cannabis and cigarettes are frequently used together [19]. Individuals who use cannabis are more likely to report cigarette use [20-22], and those who use cigarettes are more likely to report cannabis use [12,23]. The co-use of cigarettes and cannabis (i.e. use of both by the same person) is common [24-27] and has increased over time (e.g. from 4.4% in 2003–04 to 5.2% in 2011–12 among US adults [28]). Co-use of cigarettes and cannabis is associated with greater adverse physical health, mental health, drug-related and social consequences than use of either substance alone [19,27,29-32].

There are a number of potential pathways through which cannabis legalization may have an impact on cigarette and cannabis co-use or use of cigarettes alone. First, complementarity occurs when two drugs are used together to experience synergistic effects of the drugs and may be influenced by increased access to and acceptance of cannabis driven by legalization. Cannabis and tobacco are typically used by the same route of administration (i.e. inhalation) and are often used simultaneously (i.e. thorough blunts or joints [19]), increasing the amount of tetrahydrocannabinol (THC) inhaled [33,34]. THC increases the rewarding value of nicotine (e.g. [35-38]), and some individuals report using tobacco to enhance the effects of cannabis [36,37]. A second factor may be substitution: the replacement of one drug with another, which has been described as a reason for cannabis use [39-41]. In this case, individuals may choose cannabis over cigarettes as an alternative substance that is viewed as less addictive, less harmful and more acceptable [17,42], or individuals may use one drug to alleviate some of the potential negative effects of the other drug (e.g. to attenuate withdrawal [43-45]).

Despite the relationship between cannabis and cigarette use, the increased negative consequences associated with co-use and the increasing use and acceptance of cannabis alongside increasing cannabis legalization, little is known about how cannabis legalization might impact upon the co-use of cigarettes and cannabis versus the use of cigarettes without cannabis or cannabis without cigarettes. One US national study reported a higher prevalence of cigarette–cannabis co-use in states with versus without MCL in 2013 (5.8 versus 4.8%, P < 0.01) [46], whereas another study [47] found that per capita cigarette sales did not differ overall for states with versus without MCL or RCL. Similarly, several studies showed no RCL-related changes in cigarette use [48,49] or cannabis use [50] among young adults.

It is not known whether the co-use of cigarettes and cannabis has changed in recent years by cannabis legal status. Further, despite well-documented disparities in cigarette use by demographics (e.g. a higher cigarette smoking prevalence for men versus women, white versus black individuals and those with lower versus higher education) [6], it is not known whether similar disparities will emerge in the co-use of cigarettes and cannabis in relation to the legalization of cannabis.

The current study addresses two aims. First, the study investigated whether MCL or RCL were associated with changes in the prevalence of co-use of cigarettes and cannabis, singular use of cigarettes and singular use of cannabis from pre- to post-legalization. Secondly, the study examined whether changes in the prevalence of cigarette–cannabis co-use, singular use of cigarettes and singular use of cannabis from pre- to post-legalization of cannabis for recreational or medical use varied by socio-demographics.

METHODS

The National Survey on Drug Use and Health (NSDUH) is an annual cross-sectional survey based on a multi-stage probability sample of the US non-institutionalized population. Data from the 2004–17 NSDUH public and restricted-use files were used, providing a total combined sample of 783 663. Sampling weights for the NSDUH were computed to control for unit-level and individual-level non-response and adjusted to ensure consistency with population estimates obtained from the US Census Bureau. To use information from the 14 years of combined data, a new weight was created upon aggregating the 14 data sets by dividing the original weight by the number of data sets combined. Additional information describing the complex sampling weight methodology for the NSDUH can be found elsewhere [51]. Information regarding state of residence was used to determine state-level cannabis laws and these data, which are restricted-use variables, were accessed through the Research Data Center. Analysis of de-identified data from the survey is exempt from the federal regulations for the protection of human research participants. Analysis of restricted data through the National Center for Health Statistics (NCHS) Research Data Center was approved by the NCHS Ethics Review Board.

Measures

Cannabis legalization

Cannabis legalization was defined by the presence of enacted medical (MCL) or recreational cannabis laws (RCL). Dates of enactment are provided in Supporting information, Table S1. The time-varying indicators for MCL and RCL were ‘0’ in years before enactment and ‘1’ in all subsequent years for MCL and RCL, respectively (states can be ‘1’ for MCL and ‘1’ for RCL within the same year). See Statistical analysis section for more details.

Cannabis and cigarette use

Respondents reported how long it had been since their last cannabis use. Individuals reporting the use of cannabis ‘within the past 30 days’ were categorized as having past-month cannabis use and other respondents were categorized as having no past-month cannabis use. Respondents were also categorized according to their past-month cigarette use. Past-month cigarette use was defined as any reported cigarette use in the past month, and those who did not report cigarette use in the past month were categorized as having no past-month cigarette use. Definitions of cigarette use and cannabis use were consistent with past research [46]. From these two items, four mutually exclusive use categories were created: (1) past-month co-use of cigarettes and cannabis, (2) past-month cigarette-only use (i.e. no past-month cannabis use), (3) past-month cannabis-only use (i.e. no past-month cigarette use) and (4) past-month non-use of cigarettes and cannabis.

Socio-demographic variables

Socio-demographic variables for this study included gender (male, female), race/ethnicity [non-Hispanic (NH) white, NH black, Hispanic, NH other (i.e. Native American/Alaska Native, Native Hawaiian/other Pacific Islander, Asian, more than one race)], age (12–17, 18–25, 26–34, 35–49, 50+ years), total annual household income (< $20 000, 20 000–74 999, ≥ 75 000), marital status (married, widowed/divorced/separated, never married) and education (less than high school, high school graduate, some college, college graduate or higher).

Statistical analysis

First, we assessed the impact of both medical and recreational cannabis legalization over time (2004–17) on past-month use of cigarette and/or cannabis (versus no past-month use of cigarettes or cannabis) using difference-in-difference (DID) models. Two-way fixed-effects models that included fixed effects for calendar year and state of residence, as well as time-varying indicators for MCL and RCL, were estimated to gain crude DID estimates. Models were then adjusted for socio-demographic variables (i.e. gender, race/ethnicity, age, income, education). DID estimates reflect the effect of MCL or RCL in states that passed the law during the study period (MCL: AR, AZ, CT, DC, DE, FL, IL, LA, MA, MI, MN, MO, NH, NJ, NM, NY, ND, OH, PA, RI, VT, WV; RCL: AK, CA, CO, DC, MA, ME, NV, OR, WA) versus all other states (control states) by contrasting changes in the outcome of interest from before to after MCL or RCL to changes in states that did not pass the law during the same time-period. DID estimates are expressed as odds ratios with 95% confidence intervals and indicate the change in the odds of cannabis–cigarette use over time in states that passed an MCL or RCL compared to states that did not pass these laws during the study period.

Secondly, differences in DID estimates across socio-demographic strata were explored by including interaction terms between the socio-demographic factor of interest and both time-varying indicators for MCL and RCL. The P-value for the interaction term (denoted P_int in the tables) indicates whether the strength of association varies between a specific socio-demographic grouping versus the reference group. Models were adjusted for all socio-demographic variables other than the characteristic of interest. Stratum-specific DID estimates were obtained using the ‘effects’ command.

We also examined the prevalence of cannabis–cigarette use in 2017 (n = 56 276), the most recent year of available data at the time when the study was conducted, overall by socio-demographics and by 2017 cannabis laws. The 2017 legalization status included three categories: RCL and MCL (all RCL states also had MCL), MCL and no RCL and no MCL/RCL (see Supporting information, Table S1). No states had RCL and no MCL.

All analyses were conducted using SAS-callable SUDAAN and incorporated survey weights for all analyses. The analysis was not pre-registered, and the results should be considered exploratory.

RESULTS

Estimates of impact of cannabis legalization on past-month co-use of cigarettes and cannabis

MCL

MCL were associated with an overall increase in past-month cigarette–cannabis co-use (see Table 1). The association between MCL and co-use was of the highest magnitude among those ages 50+ years, widowed/divorced/separated, who identified as NH black, and with a college degree or above. Notably, adolescents between the ages of 12 and 17 years experienced decreased odds of co-use associated with MCL.

TABLE 1.

Difference-in-difference estimates for past-month co-use of cigarettes and cannabis

Adjusted DID estimate
MCL aOR (95% CI) P_int RCL aOR (95% CI) P_int
Overall 1.087 (1.024, 1.155) 1.061 (0.955, 1.178)
Age (years)
 12–17 0.832 (0.764, 0.906) < 0.001 0.645 (0.513, 0.810) < 0.001
 18–25 0.966 (0.906, 1.029) 0.015 0.840 (0.733, 0.963) 0.014
 25–34 1.064 (0.976, 1.159) Ref. 1.076 (0.919, 1.261) Ref.
 35–49 1.153 (1.056, 1.258) 0.108 1.242 (1.049, 1.471) 0.190
 50+ 1.599 (1.391, 1.838) < 0.001 1.374 (1.028, 1.836) 0.120
F(4) = 25.754 (P < 0.001) F(4) = 8.421 (P < 0.001)
Gender
 Male 1.082 (1.013, 1.155) 0.662 1.031 (0.910, 1.168) 0.382
 Female 1.097 (1.022, 1.178) Ref. 1.112 (0.961, 1.286) Ref.
F(1) = 0.191 (P = 0.662) F(1) = 0.763 (P = 0.382)
Marital status
 Married 1.188 (1.074, 1.313) 0.001 1.240 (1.023, 1.504) 0.012
 Widowed/divorced/separated 1.305 (1.160, 1.469) < 0.001 1.212 (0.959, 1.531) 0.056
 Never married 1.023 (0.957, 1.093) Ref. 0.947 (0.836, 1.074) Ref.
F(2) = 12.347 (P < 0.001) F(2) = 3.958 (P = 0.019)
Income
 < $20 000 1.122 (1.040, 1.211) 0.382 1.160 (0.944, 1.425) 0.109
 $20 000–74 000 1.064 (0.986, 1.148) 0.646 1.129 (0.968, 1.317) 0.087
 ≥ $75 000 1.084 (1.007, 1.167) Ref. 0.956 (0.831, 1.099) Ref.
F(2) = 0.853 (P = 0.426) F(2) = 2.007 (P = 0.135)
Race/ethnicity
 Non-Hispanic white 1.106 (1.037, 1.180) Ref. 1.037 (0.915, 1.175) Ref.
 Non-Hispanic black 1.143 (1.024, 1.276) 0.563 1.165 (0.803, 1.690) 0.544
 Hispanic 0.973 (0.871, 1.088) 0.019 1.038 (0.834, 1.292) 0.993
 Non-Hispanic other 0.934 (0.814, 1.072) 0.015 1.240 (0.975, 1.578) 0.164
F(3) = 3.697 (P = 0.011) F(3) = 0.747 (P = 0.524)
Educational attainment
 Less than high school 1.026 (0.932, 1.130) 0.049 1.118 (0.860, 1.453) 0.400
 High school or equivalent 1.145 (1.057, 1.241) 0.816 1.043 (0.874, 1.244) 0.586
 Some college 1.055 (0.974, 1.144) 0.104 1.073 (0.919, 1.252) 0.453
 College graduate or above 1.160 (1.043, 1.291) Ref. 0.973 (0.791, 1.197) Ref.
F(3) = 2.642 (P = 0.048) F(3) = 0.287 (P = 0.835)
Open in a new tab

aOR = adjusted odds ratio; CI = confidence interval; DID = difference-in-difference; MCL = medical cannabis laws; P_int: P-value for the interaction term; RCL = recreational cannabis laws.

Adjusted analyses were adjusted for the other socio-demographic variables listed in the table.

RCL

RCL were not associated with an overall change in past-month cigarette–cannabis co-use. However, this association between RCL and cigarette–cannabis co-use varied by age and marital status, such that the increase was greatest among respondents aged 50+ years and among respondents who were married. Similar to MCL, RCL were associated with a decrease in the odds of co-use among adolescents aged 12–17 years.

Estimates of impact of cannabis legalization on past-month cigarette-only use

MCL

Overall, MCL were not associated with a change in past-month cigarette-only use (see Table 2). However, the association between MCL and cigarette-only use varied by age and race/ethnicity. There was a significant decrease in cigarette-only use among those aged 12–17 years and a significant increase in cigarette-only use among those aged 50 years and older. NH black individuals reported an increase in cigarette-only use with MCL compared with no change in cigarette-only use among NH white individuals.

TABLE 2.

Difference-in-difference estimates for past-month use of cigarettes only (no cannabis)

Adjusted DID estimate
MCL aOR (95% CI) P_int RCL aOR (95% CI) P_int
Overall 0.978 (0.936, 1.022) 0.886 (0.814, 0.966)
Age (years)
 12–17 0.766 (0.714, 0.822) < 0.001 0.550 (0.410, 0.737) 0.029
 18–25 0.889 (0.845, 0.936) 0.061 0.773 (0.690, 0.866) 0.769
 25–34 0.939 (0.885, 0.996) Ref. 0.794 (0.688, 0.915) Ref.
 35–49 0.954 (0.905, 1.006) 0.588 0.869 (0.765, 0.986) 0.326
 50+ 1.074 (1.010, 1.142) < 0.001 1.023 (0.872, 1.200) 0.010
F(4) = 20.027 (P < 0.001) F(4) = 4.943 (P = 0.001)
Gender
 Male 0.999 (0.951, 1.049) 0.062 0.880 (0.787, 0.983) 0.832
 Female 0.957 (0.910, 1.006) Ref. 0.893 (0.800, 0.998) Ref.
F(1) = 3.485 (P = 0.062) F(1) = 0.045 (P = 0.832)
Marital status
 Married 0.956 (0.904, 1.010) 0.964 0.891 (0.784, 1.012) 0.162
 Widowed/divorced/separated 1.039 (0.975, 1.108) 0.009 1.007 (0.842, 1.203) 0.019
 Never married 0.957 (0.909, 1.007) Ref. 0.801 (0.719, 0.893) Ref.
F(2) = 3.953 (P = 0.019) F(2) = 3.204 (P = 0.041)
Income
 < $20 000 0.995 (0.938, 1.054) 0.564 0.985 (0.828, 1.171) 0.085
 $20 000–74 000 0.968 (0.915, 1.023) 0.700 0.906 (0.797, 1.029) 0.282
 ≥ $75 000 0.978 (0.929, 1.029) Ref. 0.829 (0.736, 0.933) Ref.
F(2) = 0.382 (P = 0.682) F(2) = 1.650 (P = 0.192)
Race/ethnicity
 Non-Hispanic white 0.953 (0.909, 1.000) Ref. 0.807 (0.729, 0.894) Ref.
 Non-Hispanic black 1.160 (1.064, 1.265) < 0.001 1.188 (0.887, 1.590) 0.012
 Hispanic 0.967 (0.894, 1.047) 0.701 0.940 (0.790, 1.119) 0.121
 Non-Hispanic Other 0.943 (0.853, 1.042) 0.825 1.129 (0.905, 1.409) 0.005
F(3) = 6.651 (P < 0.001) F(3) = 4.567 (P = 0.003)
Educational attainment
 Less than high school 0.927 (0.866, 0.991) 0.512 0.992 (0.823, 1.197) 0.085
 High school or equivalent 0.989 (0.935, 1.046) 0.302 0.857 (0.749, 0.980) 0.459
 Some college 1.004 (0.949, 1.063) 0.156 0.913 (0.801, 1.042) 0.200
 College graduate or above 0.952 (0.888, 1.020) Ref. 0.789 (0.654, 0.952) Ref.
F(3) = 2.025 (P = 0.108) F(3) = 1.118 (P = 0.341)
Open in a new tab

aOR = adjusted odds ratio; CI = confidence interval; DID = difference-in-difference; MCL = medical cannabis laws; P_int = P-value for the interaction term; RCL = recreational cannabis laws.

Adjusted analyses were adjusted for the other socio-demographic variables listed in the table.

RCL

Overall, RCL were associated with a decrease in past-month cigarette-only use. The association between RCL and cigarette-only use varied by age, marital status and race/ethnicity. The decrease in cigarette-only use was greatest among respondents aged 12–17 years. Never married individuals (the reference group) demonstrated a decrease in cigarette-only use while the other marital statuses demonstrated no significant change in cigarette-only use. NH white individuals (the reference group) demonstrated a decrease in cigarette only-use while cigarette-only use did not change significantly for the other racial/ethnic groups.

Estimates of impact of cannabis legalization on past-month cannabis-only use

MCL

Overall, MCL were not associated with a change in past-month cannabis-only use (see Table 3). However, the association between MCL and cannabis-only use varied by age, gender, marital status, race/ethnicity and education. There was a significant decrease in cannabis-only use with MCL among those aged 12–17 years, a significant increase in cannabis-only use among those aged 50 years and older and no change in cannabis-only use for the other groups. While the change in cannabis-only use was not significant for men or women, the trends were in opposite directions (i.e. decrease in cannabis use for men and increase in cannabis use for women). There was an increase in cannabis-only use with MCL for those who were widowed, divorced or separated and no change for the other marital status groups. Those who identified as Hispanic reported a decrease in cannabis-only use with MCL while there were no changes in cannabis-only use for the other racial/ethnic groups. Finally, those with the lowest educational attainment reported a decrease in cannabis-only use while all other education groups reported no change in cannabis-only use.

TABLE 3.

Difference-in-difference estimates for past-month use of cannabis only (no cigarettes)

Adjusted DID estimate
MCL aOR (95% CI) P_int RCL aOR (95% CI) P_int
Overall 1.021 (0.947, 1.101) 1.206 (1.088, 1.336)
Age (years)
 12–17 0.898 (0.820, 0.983) 0.014 0.737 (0.624, 0.871) < 0.001
 18–25 0.954 (0.882, 1.033) 0.146 0.964 (0.855, 1.087) < 0.001
 25–34 1.032 (0.920, 1.157) Ref. 1.401 (1.178, 1.666) Ref.
 35–49 0.983 (0.884, 1.094) 0.471 1.374 (1.163, 1.623) 0.868
 50+ 1.241 (1.070, 1.438) 0.030 1.338 (1.068, 1.676) 0.740
F(4) = 5.956 (P < 0.001) F(4) = 14.988 (P < 0.001)
Gender
 Male 0.986 (0.908, 1.070) 0.017 1.099 (0.977, 1.237) 0.005
 Female 1.079 (0.990, 1.176) Ref. 1.365 (1.190, 1.566) Ref.
F(1) = 5.654 (P = 0.017) F(1) = 7.844 (P = 0.005)
Marital status
 Married 1.099 (0.980, 1.232) 0.002 1.345 (1.139, 1.587) 0.020
 Widowed/divorced/separated 1.179 (1.012, 1.373) 0.002 1.351 (1.063, 1.715) 0.094
 Never married 0.939 (0.863, 1.022) Ref. 1.095 (0.972, 1.233) Ref.
F(2) = 7.979 (P < 0.001) F(2) = 3.388 (P = 0.034)
Income
 < $20 000 1.001 (0.908, 1.104) 0.233 1.177 (0.983, 1.409) 0.917
 $20 000–74 000 0.965 (0.875, 1.064) 0.045 1.244 (1.062, 1.458) 0.638
 ≥ $75 000 1.060 (0.973, 1.154) Ref. 1.189 (1.041, 1.359) Ref.
F(2) = 2.092 (P = 0.124) F(2) = 0.148 (P = 0.863)
Race/ethnicity
 Non-Hispanic white 1.077 (0.993, 1.168) Ref. 1.211 (1.078, 1.360) Ref.
 Non-Hispanic black 0.983 (0.876, 1.104) 0.109 0.955 (0.719, 1.269) 0.106
 Hispanic 0.833 (0.732, 0.949) < 0.001 1.305 (1.048, 1.626) 0.541
 Non-Hispanic other 0.871 (0.738, 1.027) 0.008 1.231 (0.968, 1.566) 0.895
F(3) = 7.173 (P < 0.001) F(3) = 1.163 (P = 0.323)
Educational attainment
 Less than high school 0.780 (0.676, 0.901) < 0.001 1.399 (1.089, 1.798) 0.584
 High school or equivalent 1.050 (0.939, 1.173) 0.871 1.153 (0.950, 1.400) 0.322
 Some college 1.019 (0.924, 1.125) 0.480 1.141 (0.983, 1.324) 0.177
 College graduate or above 1.060 (0.951, 1.181) Ref. 1.295 (1.100, 1.525) Ref.
F(3) = 6.059 (P < 0.001) F(3) = 1.172 (P = 0.319)
Open in a new tab

aOR = adjusted odds ratio; CI = confidence interval; DID = difference-in-difference; MCL = medical cannabis laws; P_int = P-value for the interaction term; RCL = recreational cannabis laws.

Adjusted analyses were adjusted for the other socio-demographic variables listed in the table.

RCL

RCL were associated with an overall increase in past-month cannabis-only use. The association between RCL and cannabis-only use varied by age, gender and marital status. The youngest age group reported a decrease in cannabis-only use with RCL while most of the older age groups (aged 25 years and above) reported an increase in cannabis-only use with RCL. Women reported an increase in cannabis-only use while men reported no change in cannabis-only use. Those never married reported no change in cannabis-only use with RCL while the other marital groups reported increases in cannabis-only use.

Past-month cigarette–cannabis co-use in 2017

In the most recent data year (2017), 4.37% of individuals reported cigarette–cannabis co-use, 13.52% reported cigarette-only use and 5.18% reported cannabis-only use. Cigarette–cannabis co-use was highest among states with RCL and MCL, followed by states with MCL and no RCL, and finally states with no RCL or MCL (see Supporting information, Table S2). This pattern was similar for cannabis-only use but not for cigarette-only use, where the highest prevalence was in states with no RCL or MCL, followed by states with MCL and no RCL, and finally states with RCL and MCL. See Supporting information, Table S2 for the 2017 prevalence of cigarette and cannabis use by demographics.

DISCUSSION

This study identified several novel findings regarding the potential impact of cannabis legalization on use of cannabis and cigarettes. First, during the study period (2004–17), MCL was associated with an increase in cigarette–cannabis co-use except in youth under age 18 years, among whom cigarette–cannabis co-use decreased. Secondly, RCL was not associated with a change in cigarette–cannabis co-use in the overall sample but was associated with a decline in cigarette-only use in the overall sample and among various sociodemographic groups. MCL was not associated with a change in cigarette-only use overall, but increases were observed among those aged 50 years and older and among NH black individuals. In 2017, cigarette–cannabis co-use was highest among individuals residing in states with RCL followed by those in states with MCL, with the lowest prevalence found among those residing in states without RCL or MCL.

While attention has been paid to the impact of cannabis legalization on the prevalence of cannabis use [50,52], few studies have evaluated the implications of cannabis policy for cigarette use or co-use of cigarettes and cannabis. Further, as most prior research examined adolescents [50,53], little is known about cannabis policy and cigarette use among adults. Bhave & Murthi [54] found that RCL was associated with increases in cigarette sales in Colorado, while Choi and colleagues [55] found that MCL was associated with a decrease in cigarette use in US national data. Our study found, in contrast, that RCL was associated with an overall decrease in cigarette-only use and MCL was not associated with an overall change in cigarette-only use. Further, MCL was related to an increase in co-use while RCL was not related to a change in co-use. These differences in the relationship of MCL and RCL to co-use versus solo use underscore the need to examine all three of these outcome variables to best understand the impacts of cannabis laws.

Several age-specific changes in cigarette and cannabis use were identified. Decreases in cigarette-only use and cannabis-only use were observed among youth with MCL and RCL while increases in cigarette-only use with MCL and increases in cannabis-only use with MCL and RCL were observed among older adults (aged 50+). Past research on adolescents and cannabis laws have shown mixed results. Two studies using data from the US Monitoring the Future study (2010–15 and 1991–2015) found a decrease in cigarette use among adolescents with MCL [56,57], similar to our study, although there were increases in cigarette use among 12th graders after MCL [56]. Other studies of adolescences and young adults found no change in cigarette use with MCL or RCL [48,49,58] and one study found increases in cannabis use by adolescents after RCL [59]. It should be noted that some of the strongest effects of legalization were found among the age subgroups with the lowest prevalences of use (e.g. those aged under 18 and over 50 years), suggesting the need to start examining the impact on use in groups with lower prevalences among whom changes in behavior may be more pronounced.

As discussed earlier, mechanisms by which cannabis legalization and the societal changes that may accompany it will impact both cannabis and cigarette use are probably varied and complex. Complementarity of cannabis and cigarettes was suggested by previous work showing that cigarette use increased from 2002 to 2015 among US individuals who use cannabis [12] and by the current study based on the increase in cigarette–cannabis co-use among states with MCL and among some socio-demographic subgroups in states with RCL. Conversely, we also found that RCL were associated with decreased cigarette-only use and increased cannabis-only use potentially due to more people substituting cannabis for cigarettes. Future research should further examine complementarity versus substitution of cannabis and cigarettes in relation to cannabis laws through longitudinal studies and measures that assess patterns of use and reasons for using one or both substances. Additional research can also examine whether specific individuals are more likely to engage in complementarity versus substitution and whether some individuals engage in both complementarity and substitution depending upon the context.

With regard to limitations, the NSDUH includes non-institutionalized US individuals aged 12 years and older and results may not generalize to other groups, such as individuals outside the United States. Secondly, some racial/ethnic groups had to be combined into an ‘NH other’ group due to sample sizes, and differences among specific subgroups in this category may be obscured [60]. Thirdly, data on cannabis and cigarette use were self-reported and may have been subject to biases, memory errors or under-reporting.

Fourthly, this study did not examine modes of administration of cigarettes and cannabis. There are a number of modes of co-administering both cannabis and other tobacco products simultaneously (e.g. mixing tobacco with cannabis to create spliffs or mulled cigarettes, adding cannabis to a hollowed-out cigar to create blunts [19]). Along with recent increases in the use and number of products on the market that are used to co-administer tobacco and cannabis, it is increasingly critical to examine these outcomes in future studies.

Fifthly, while cigarettes remain the most commonly used tobacco product by US adults [6], e-cigarettes are the most commonly used tobacco product by youth [61] and e-cigarette use is associated with cannabis use among youth [62]. Further, the use of cannabis via e-cigarettes/vaping devices has increased among US youth, especially among states with MCL and RCL [63]. Future studies that examine how e-cigarette use may play a role in the relationship of cigarette and cannabis use in relation to RCL/MCLs are needed, especially among youth.

Sixthly, cannabis legalization status in each state was based on the date legalization law was passed. This approach, while widely used in MCL/RCL research, has a set of limitations. Most notably, MCL and RCL laws have been in place for different amounts of time and vary among states and by smaller geographies (e.g. counties and localities) in ways that may directly influence the monetary price of cannabis (e.g. tax level, discounting restrictions) or access and exposure to cannabis suppliers (e.g. restrictions on the number or density of cannabis retailers; home cultivation limits). Future studies should strive to consider these complex and intertwined policies.

Seventhly, there are factors not examined in the current analyses that could be related to the relationship of cannabis laws and cigarette–cannabis co-use such as urbanicity and state-level tobacco control policies as well as changes in tobacco control policies over time. Finally, our analyses were conducted up to 2017. Analyses with newer years of data, as they become available, should continue to examine the relationship of cannabis laws and cigarette–cannabis co-use, cigarette-only use and cannabis-only use, especially as new cannabis laws are passed in US states. Finally, a number of these findings were of modest magnitude, although at a population-level these effects can translate into substantial public health issues in terms of impact upon sizable population segments affecting millions of individuals, as well as having large societal impacts and healthcare costs.

CONCLUSIONS

Given the relationships of MCL and RCL to cigarette and cannabis use, understanding the impact of cannabis legalization on the use of both cannabis and cigarettes, as well as the use of either alone, is critical to mitigating potential unintended consequences of changing cannabis policy on tobacco control.

Supplementary Material

supplemental table 1
supplemental table 2

Additional supporting information may be found in the online version of the article at the publisher’s website.

ACKNOWLEDGEMENTS

This work was supported by National Institutes of Health/National Institute on Drug Abuse (RDG, grant number R01-DA20892).

Footnotes

DECLARATION OF INTERESTS

None.

REFERENCES

  • 1.US Department of Health and Human Services (USDHHS). The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. USDHHS, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health: Atlanta, GA; 2014. [Google Scholar]
  • 2.World Health Organization (WHO). WHO Global Report: Mortality Attributable to Tobacco. Geneva, Switzerland: WHO Press; 2012. [Google Scholar]
  • 3.Global Burden of Disease (GBD) 2015 Tobacco Collaborators. Smoking prevalence and attributable disease burden in 195 countries and territories, 1990–2015: a systematic analysis from the global burden of disease study 2015. Lancet. 2017;389:1885–906. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.World Health Organization (WHO). WHO Global Report on Trends in Prevalence of Tobacco Smoking 2000–2025. 2nd ed. Geneva, Switzerland: WHO Press; 2018. [Google Scholar]
  • 5.Carter BD, Abnet CC, Feskanich D, Freedman ND, Hartge P, Lewis CE, et al. Smoking and mortality—beyond established causes. N Engl J Med. 2015;372:631–40. [DOI] [PubMed] [Google Scholar]
  • 6.Cornelius ME, Wang TW, Jamal A, Loretan CG, Neff LJ. Tobacco product use among adults—United States, 2019. Morb Mortal Wkly Rep. 2020;69:1736–42. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Weinberger AH, Gbedemah M, Wall MM, Hasin DS, Zvolensky MJ, Goodwin RD. Cigarette use is increasing among people with illicit substance use disorders in the United States, 2002–14: emerging disparities in vulnerable populations. Addiction. 2018;113:719–28. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Weinberger AH, Chaiton MO, Zhu J, Wall MM, Hasin DS, Goodwin RD. Trends in the prevalence of current, daily, and nondaily cigarette smoking and quit ratios by depression status in the U.S.: 2005–17. Am J Prev Med. 2020;58:691–8. [DOI] [PubMed] [Google Scholar]
  • 9.Streck JM, Weinberger AH, Pacek LR, Gbedemah M, Goodwin RD. Cigarette smoking quit rates among persons with serious psychological distress in the United States from 2008 to 2016: are mental health disparities in cigarette use increasing? Nicotine Tob Res. 2020;22:130–4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Garrett BE, Martell BN, Caraballo RS, King BA. Socioeconomic differences in cigarette smoking among sociodemographic groups. Prev Chronic Dis. 2019;16:1–6, E74. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Hasin DS, Kerridge BT, Saha TD, Huang B, Pickering R, Smith SM, et al. Prevalence and correlates of DSM-5 cannabis use disorder, 2012–2013: findings from the National Epidemiologic Survey on Alcohol and Related Conditions—III. Am J Psychiatry. 2016;173:588–99. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Goodwin RD, Pacek LR, Copeland J, Moeller SJ, Dierker L, Weinberger A, et al. Trends in daily cannabis use among cigarette smokers: United States, 2002–2014. Am J Public Health. 2018;108:137–42. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Compton WM, Han B, Jones CM, Blanco C, Hughes A. Marijuana use and use disorders in adults in the USA, 2002–14: analysis of annual cross-sectional surveys. Lancet Psychiatry. 2016;3:954–64. [DOI] [PubMed] [Google Scholar]
  • 14.Azofeifa A, Mattson ME, Schauer G, McAfee T, Grant A, Lyerla R. National estimates of marijuana use and related indicators—National Survey on Drug Use and Health, United States, 2002–2014. Morb Mortal Wkly Rep Surveill Summ. 2016;65:1–25. [DOI] [PubMed] [Google Scholar]
  • 15.Grucza RA, Agrawal A, Krauss MJ, Cavazos-Rehg PA, Bierut LJ. Recent trends in the prevalence of marijuana use and associated disorders in the United States. JAMA Psychiatry. 2016;73:300–1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Swift A. Gallup Poll: for first time, Americans favor legalizing marijuana 2013. Available at: https://www.gallup.com/poll/165539/first-time-americans-favor-legalizing-marijuana.aspx [Google Scholar]
  • 17.Pacek LR, Mauro PM, Martins SS. Perceived risk of regular cannabis use in the United States from 2002 to 2012: differences by sex, age, and race/ethnicity. Drug Alcohol Depend. 2015;149:232–44. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Pacek LR, Weinberger AH, Zhu J, Goodwin RD. Rapid increase in the prevalence of cannabis use among people with depression in the United States, 2005–17: the role of differentially changing risk perceptions. Addiction. 2020;115:935–43. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Schauer GL, Rosenberry ZR, Peters EN. Marijuana and tobacco co-administration in blunts, spliffs, and mulled cigarettes: a systematic literature review. Addict Behav. 2017;64:200–11. [DOI] [PubMed] [Google Scholar]
  • 20.Weinberger AH, Funk AP, Goodwin RD. A review of epidemiologic research on smoking behavior among persons with alcohol and illicit substance use disorders. Prev Med. 2016;92:148–59. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.Richter KP, Kaur H, Resnicow K, Nazir N, Mosier MC, Ahluwalia JS. Cigarette smoking among marijuana users in the United States. Subst Abuse. 2004;25:35–43. [DOI] [PubMed] [Google Scholar]
  • 22.Schauer GL, Berg CJ, Kegler MC, Donovan DM, Windle M. Differences in tobacco product use among past month adult marijuana users and nonusers: findings from the 2003–2012 National Survey on drug use and health. Nicotine Tob Res. 2016;18:281–8. [DOI] [PubMed] [Google Scholar]
  • 23.Strong DR, Myers MG, Pulvers K, Noble M, Brikmanis K, Doran N. Marijuana use among US tobacco users: findings from wave 1 of the Population Assessment of Tobacco Health (PATH) study. Drug Alcohol Depend. 2018;186:16–22. [DOI] [PubMed] [Google Scholar]
  • 24.Agrawal A, Budney AJ, Lynskey MT. The co-occurring use and misuse of cannabis and tobacco: a review. Addiction. 2012;107:1221–33. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Agrawal A, Lynskey MT, Madden PA, Pergadia ML, Bucholz KK, Heath AC. Simultaneous cannabis and tobacco use and cannabis-related outcomes in young women. Drug Alcohol Depend. 2009;101:8–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Ramo DE, Liu H, Prochaska JJ. Tobacco and marijuana use among adolescents and young adults: a systematic review of their co-use. Clin Psychol Rev. 2012;32:105–21. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Hindocha C, Brose LS, Walsh H, Cheeseman H. Cannabis use and co-use in tobacco smokers and non-smokers: Prevalence and associations with mental health in a cross-sectional, nationally representative sample of adults in Great Britain, 2020. Addiction. 2021;116:2209–19. [DOI] [PubMed] [Google Scholar]
  • 28.Schauer GL, Berg CJ, Kegler MC, Donovan DM, Windle M. Assessing the overlap between tobacco and marijuana: trends in patterns of co-use of tobacco and marijuana in adults from 2003–2012. Addict Behav. 2015;49:26–32. [DOI] [PubMed] [Google Scholar]
  • 29.Peters EN, Budney AJ, Carroll KM. Clinical correlates of co-occurring cannabis and tobacco use: a systematic review. Addiction. 2012;107:1404–17. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Tucker JS, Pedersen ER, Seelam R, Dunbar MS, Shih RA, D’Amico EJ. Types of cannabis and tobacco/nicotine co-use and associated outcomes in young adulthood. Psychol Addict Behav. 2019;33:401–11. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Meier E, Hatsukami DK. A review of the additive health risk of cannabis and tobacco co-use. Drug Alcohol Depend. 2016;166:6–12. [DOI] [PubMed] [Google Scholar]
  • 32.Peters EN, Schwartz RP, Wang S, O’Grade KE, Blanco C. Psychiatric, psychosocial, and physical health correlates of co-occurring cannabis disorders and nicotine dependence. Drug Alcohol Depend. 2014;134:228–34. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.Meng Y, Lichtman A, Bridgen D, Martin B. Inhalation studies with drugs of abuse. NIDA Res Monogr. 1997;173:201–24. [PubMed] [Google Scholar]
  • 34.Van der Kooy F, Pomahacova B, Verpoorte R. Cannabis smoke condensate II: influence of tobacco on tetrahydrocannabinol levels. Inhal Toxicol. 2009;21:87–90. [DOI] [PubMed] [Google Scholar]
  • 35.Panlilio LV, Zanettini C, Barnes C, Solinas M, Goldberg SR. Prior exposure to THC increases the addictive effects of nicotine in rats. Neuropsychopharmacology. 2013;38:1198–208. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Tullis LM, Dupont R, Frost-Pineda K, Gold MS. Marijuana and tobacco; a major connection? J Addict Dis. 2003;22:51–62. [DOI] [PubMed] [Google Scholar]
  • 37.Rabin RA, George TP. A review of co-morbid tobacco and cannabis use disorders: possible mechanisms to explain high rates of co-use. Am J Addict. 2015;24:105–16. [DOI] [PubMed] [Google Scholar]
  • 38.Penetar D, Kouri E, Gross M, McCarthy E, Rhee C, Peters E, et al. Transdermal nicotine alters some of marihuana’s effects in male and female volunteers. Drug Alcohol Depend. 2005;79:211–23. [DOI] [PubMed] [Google Scholar]
  • 39.Centers for Disease Control and Prevention (CDC). Vital signs: current cigarette smoking among adults aged ≥18 years with mental illness—United States, 2009–2011. Morb Mortal Weekly Rep. 2013;62:1–7. [PMC free article] [PubMed] [Google Scholar]
  • 40.Reiman A. Cannabis as a substitute for alcohol and other drugs. Harm Reduct J. 2009;6:35. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 41.Walsh Z, Callaway R, Belle-Isle L, Capler R, Kay R, Lucas P, et al. Cannabis for therapeutic purposes: patient characteristics, access, and reasons for use. Int J Drug Policy. 2013;24:511–6. [DOI] [PubMed] [Google Scholar]
  • 42.Carliner H, Brown QL, Sarvet AL, Hasin DS. Cannabis use, attitudes, and legal status in the U.S.: a review. Prev Med. 2017;104:13–23. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 43.Levin K, Copersino M, Heishman S, Liu F, Kelly D, Boggs D, et al. Cannabis withdrawal symptoms in non-treatment-seeking adult cannabis smokers. Drug Alcohol Depend. 2010;11:120–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 44.Balerio GN, Aso E, Berrendero F, Murtra P, Maldonado R. Delta9-tetrahydrocannabinol decreases somatic and motivational manifestations of nicotine withdrawal in mice. Eur J Neurosci. 2004;20:2737–48. [DOI] [PubMed] [Google Scholar]
  • 45.McClure EA, Tomko RL, Salazar CA, Akbar SA, Squeglia LM, Herrmann E, et al. Tobacco and cannabis co-use: drug substitution, quit interest, and cessation preferences. Exp Clin Psychopharmacol. 2019;27:265–75. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46.Wang JB, Ramo DE, Lisha NE, Cataldo JK. Medical marijuana legalization and cigarette and marijuana co-use in adolescents and adults. Drug Alcohol Depend. 2016;166:32–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 47.Veligati S, Howdeshell S, Beeler-Stinn S, Lingam D, Allen PC, Chen LS, et al. Changes in alcohol and cigarette consumption in response to medical and recreational cannabis legalization: evidence from U.S. state tax receipt data. Int J Drug Policy. 2020;75:102585. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 48.Alley ZM, Kerr DCR, Bae H. Trends in college students’ alcohol, nicotine, prescription opioid and other drug use after recreational marijuana legalization: 2008–2018. Addict Behav. 2020;102:106212. [DOI] [PubMed] [Google Scholar]
  • 49.Kerr DCR, Bae H, Phibbs S, Kern AC. Changes in undergraduates’ marijuana, heavy alcohol and cigarette use following legalization of recreational marijuana use in Oregon. Addiction. 2017;112:1992–2001. [DOI] [PubMed] [Google Scholar]
  • 50.Cerdá M, Mauro C, Hamilton A, Levy NS, Santaella-Tenorio J, Hasin D, et al. Association between recreational marijuana legalization in the United States and changes in marijuana use and cannabis use disorder from 2008 to 2016. JAMA Psychiatry. 2020;77:165–71. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 51.Center for Behavioral Health Statistics and Quality. 2017 National Survey on Drug Use and Health: Methodological Summary and Definitions. Rockville, MD: Substance Abuse and Mental Health Services Administration; 2018. [Google Scholar]
  • 52.Hasin DS, Sarvet AL, Cerda M, Keyes KM, Stohl M, Galea S, et al. US adult illicit cannabis use, cannabis use disorder, and medical marijuana laws: 1991–1992 to 2012–2013. JAMA Psychiatry. 2017;74:579–88. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 53.Wall MM, Mauro C, Hasin DS, Keyes KM, Cerda M, Martins SS, et al. Prevalence of marijuana use does not differentially increase among youth after states pass medical marijuana laws: commentary on and reanalysis of US National Survey on drug use in households data 2002–2011. Int J Drug Policy. 2016;29:9–13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 54.Bhave A, Murthi BPS. A study of the effects of legalization of recreational marijuana on consumption of cigarettes. Available at: https://ssrn.com/abstract=3508422 or 10.2139/ssrn.3508422 [DOI] [Google Scholar]
  • 55.Choi A, Dave D, Sabia JJ. Smoke gets in your eyes, medical marijuana laws and tobacco use. Am J Health Econ. 2019;5. 10.1162/ajhe_a_00121 [DOI] [Google Scholar]
  • 56.Cerda M, Sarvet AL, Wall M, Feng T, Keyes KM, Galea S, et al. Medical marijuana laws and adolescent use of marijuana and other substances: alcohol, cigarettes, prescription drugs, and other illicit drugs. Drug Alcohol Depend. 2018;183:62–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 57.Cerdá M, Wall M, Feng T, Keyes KM, Sarvet AL, Schulenberg J, et al. Association of state recreational marijuana laws with adolescent marijuana use. JAMA Pediatr. 2017;171:142–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 58.Coley RL, Kruzik C, Ghiani M, Carey N, Hawkins SS, Baum CF. Recreational marijuana legalization and adolescent use of marijuana, tobacco, and alcohol. J Adolesc Health. 2021;69:41–9. [DOI] [PubMed] [Google Scholar]
  • 59.Paschall MJ, García-Ramírez G, Grube JW. Recreational marijuana legalization and use among California adolescents: findings from a statewide survey. J Stud Alcohol Drugs. 2021;82:103–11. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 60.Mattingly DT, Hirschtick JL, Fleischer NL. Unpacking the non-Hispanic other category: differences in patterns of tobacco product use among youth and adults in the United States, 2009–2018. J Immigr Minor Health. 2020;22:1368–72. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 61.Gentzke AS, Wang TW, Jamal A, Park-Lee E, Ren C, Cullen KA, et al. Tobacco product use among middle and high school students—United States, 2020. Morb Mortal Wkly Rep. 2020;69:1881–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 62.Luken A, Thrul J, Johnson RM. Electronic cigarette and cannabis use: results from the 2018 Maryland youth risk behavior survey. J Cannabis Res. 2021;3:21. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 63.Nicksic NE, Do EK, Barnes AJ. Cannabis legalization, tobacco prevention policies, and cannabis use in E-cigarettes among youth. Drug Alcohol Depend. 2020;206:107730. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

supplemental table 1
NIHMS2109602-supplement-supplemental_table_1.docx (19.3KB, docx)
supplemental table 2
NIHMS2109602-supplement-supplemental_table_2.docx (17.4KB, docx)

RESOURCES