Smoking Related Mortality (Excluding Lung Cancer)

Mortality among smokers is much higher than mortality among non-smokers. Therefore, it can be important to consider increased mortality attributable to smoking when smoking is included in a model, even if specific causes affected by smoking are not necessary to explicitly include in the model. See the causal framework section in the Vivarium CSU Lung Cancer Screening Concept Model Documentation for an example of when this is important.

The purpose of this cause model document is to represent the increased mortality risk associated with smoking exposure by combining the causes affected by the smoking risk factor. This specific cause model document was created to exclude lung cancer so that it can be used in a model that models the lung cancer cause directly.

Abbreviations

Abbreviation	Definition	Note
SACs	Smoking-affected causes
ACMR	All-cause mortality rate
CSMR	Cause-specific mortality rate
EMR	Excess mortality rate
RF	Risk factor

GBD 2017 Modeling Strategy

The smoking risk factor in GBD 2017 has the following outcome pairs:

tuberculosis, lower respiratory tract infections, oesophageal cancer, stomach cancer, bladder cancer, liver cancer, laryngeal cancer, lung cancer, breast cancer, cervical cancer, colorectal cancer, lip and oral cancer, nasopharyngeal cancer, other pharyngeal cancer, pancreatic cancer, kidney cancer, leukaemia, ischaemic heart disease, ischaemic stroke, haemorrhagic stroke, subarachnoid haemorrhage, atrial fibrillation and flutter, aortic aneurysm, peripheral arterial disease, chronic obstructive pulmonary disease, other chronic respiratory diseases, asthma, peptic ulcer disease, gallbladder and biliary tract diseases, Alzheimer disease and other dementias, Parkinson disease (protective), multiple sclerosis, type‐II diabetes, rheumatoid arthritis, low back pain, cataracts, macular degeneration, and fracture.

[GBD-2017-CoD-Appendix-Smoking], [GBD-2017-YLD-Appendix-Smoking]

Note

These risk-outcome pairs are consistent between GBD 2017 and GBD 2019

Cause Hierarchy

Smoking-Affected Cause IDs

Cause	Cause ID	Age group ID start	Restrictions	More detailed subcauses?	Notes
tuberculosis	297	4		True; Drug susceptible/resistant subcauses
lower respiratory tract infections	322	2
oesophageal cancer	411	8
stomach cancer	414	8
bladder cancer	474	8
liver cancer	417	8		True; Etiology sub causes
laryngeal cancer	423	8
lung cancer	426	8			Will be excluded for this cause model
breast cancer	429	8
cervical cancer	432	8	FEMALE ONLY
colorectal cancer	441	8
lip and oral cancer	444	8
nasopharyngeal cancer	447	6
other pharyngeal cancer	450	8
pancreatic cancer	456	8
kidney cancer	471	2
leukaemia	487	2		True; Subtype subcauses
ischaemic heart disease	493	8
ischaemic stroke	495	2
haemorrhagic stroke (Intracerebral hemorrhage)	496	2
subarachnoid haemorrhage	497	2
atrial fibrillation and flutter	500	11			Age group start after lung cancer
aortic aneurysm	501	8
peripheral arterial disease	502	13			Age group start after lung cancer
chronic obstructive pulmonary disease	509	4
other chronic respiratory diseases	520	2
asthma	515	5
peptic ulcer disease	527	5
gallbladder and biliary tract diseases	534	5
Alzheimer disease and other dementias	543	13			Age group start after lung cancer
Parkinson disease (protective)	544	9			Age group start after lung cancer
multiple sclerosis	546	9			Age group start after lung cancer
type‐II diabetes	976	8
rheumatoid arthritis	627	6
low back pain	630	N/A	YLD only		Exclude due to nonfatal
cataracts	671	N/A	YLD only		Exclude due to nonfatal
macular degeneration	672	N/A	YLD only		Exclude due to nonfatal
Fracture	N/A	N/A	YLD only		Exclude due to nonfatal

Note

The starting age group IDs were extracted according to the YLL start, not the YLD start.

The Vivarium CSU Lung Cancer Screening Model only models simulants 15 years (age group ID 8) and older, so notes were made for causes with age group starts older than 15 years only.

Restrictions

See the table above.

Vivarium Modeling Strategy

Scope

The Vivarium modeling strategy outlined in this document will be a mortality only model that utilizes forecasted cause-specific mortality rates for ischemic heart disease (IHD) and chronic obstructive pulmomary disease (COPD) from 2020 to 2040. These causes were selected because they represent a large share of all smoking-related mortality without needing to model several additional causes with smaller contributions. This model is intended to be pair with the smoking risk exposure model.

This model was designed for use in the Lung Cancer Screening model, which uses data forecasted from 2020 to 2040.

Assumptions and Limitations

This model is limited in that it only considers smoking attributable deaths due to IHD and COPD (as well as lung cancer when modeled as a part of the Lung Cancer Screening model) and not the totality of smoking attributable deaths.

According to GBD 2019 estimates, lung cancer, COPD, and IHD combined account for 65.6% (UI: 62.6 - 67.9) of all smoking-attributable mortaltiy in China across all age groups and both sexes. For males, the value is 64.8% and for females it is 71.1%. The calculation of these values is hosted here.

Note

If stroke (cause ID 494) were to be added to this mortality model, which would require forecasted mortality estimates, 82.1% of smoking attributable mortality among the Chinese population would be represented in our model. This was not included in the current modeling strategy due to scope constraints on the forecast models.

Cause Model Diagram

There is no cause model diagram for this cause model because it is a mortality-only model. Mortality using should be modeled as follows:

\[ \begin{align}\begin{aligned}mr_i = ACMR - CSMR_\text{426} - (\sum_{c=1}^{n} CSMR_c)\\+ EMR(i)_\text{426} * (1 - PAF_\text{426}) * RR(i)_\text{426}\\+ (\sum_{c=1}^{n} CSMR_c * (1 - PAF_c) * RR(i)_c)\end{aligned}\end{align} \]

Where,

Definitions

Parameter	Definition	Note
\(mr_i\)	Mortality rate for an individual simulant
\(ACMR\)	All cause mortality rate forecasted from 2020-2040	/ihme/csu/swiss_re/forecast
\(426\)	Lung cancer
\(c\)	509, 493, 414, 441	COPD, IHD, Stomach cancer, Colorectal cancer
\(CSMR_\text{426}\)	Cause-specific mortality rate for lung cancer forecasted from 2020-2040	Defined in the lung cancer cause model document
\(CSMR_c\)	Cause-specific mortality rate for cause \(c\), forecasted from 2020-2040	/ihme/csu/swiss_re/forecast/{c}_deaths_12_29_ng_smooth_13.nc, ‘nosed_forecast’ column
\(RR(i)_\text{c}\)	Relative risk of a given cause for an individual simulant based on their smoking exposure	Defined in the smoking risk effects documentation page
\(PAF_\text{c}\)	Population attributable fraction for smoking on mortality due to cause c	\(\frac{\overline{RR(i)_c} - 1}{\overline{RR(i)_c}}\) (details in the smoking risk effects page)
\(EMR(i)_\text{426}\)	Excess mortality rate of lung cancer for an individual simulant (based on cause model state)	Defined in the lung cancer cause model document; use forecasted 2019 value

Note

May also include cause 494 (stroke) in cause list \(c\) if/when it is added to the forecast models

Upon the event that a simulant dies according to their \(mr_i\), the probability that their cause of death was one of the following causes is represented in the table below:

Cause of death likelihoods

Cause of death	Probability	Note
Lung cancer	\(\frac{EMR(i)_\text{426} * (1 - PAF_\text{426}) * RR(i)_\text{426}}{mr_i}\)
Smoking-affected causes	\(\frac{\sum_{c=1}^{n} CSMR_c * (1 - PAF_c) * RR(i)_c}{mr_i}\)	For \(c\) in [493,509,414,441]
Other causes	\(\frac{1 - EMR(i)_\text{426} * (1 - PAF_\text{426}) * RR(i)_\text{426} + (\sum_{c=1}^{n} CSMR_c * (1 - PAF_c) * RR(i)_c)}{mr_i}\)

Validation Criteria

The simulation output should replicate the cause-specific mortality rate of smoking affected causes as defined in the data tables. Additionally, GBD all cause mortality should be replicated in the simulation output.

When simulation output is stratified on smoking status, never smokers should have lower mortality rates than current and former smokers.

References

[GBD-2017-YLD-Appendix-Smoking]

Pages ???-??? in Supplementary appendix 1 to the GBD 2017 YLD Capstone:

(GBD 2017 YLD Capstone) GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 2018; 392: 1789–858. DOI: https://doi.org/10.1016/S0140-6736(18)32279-7

[GBD-2017-CoD-Appendix-Smoking]

Pages ???-??? in Supplementary appendix 1 to the GBD 2017 CoD Capstone:

(GBD 2017 CoD Capstone) GBD 2017 Causes of Death Collaborators. Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 2018; 392: 1736–88. DOI: http://dx.doi.org/10.1016/S0140-6736(18)32203-7