Smoking, Vaping and Chronic Disease in England: Why Smoking History Matters

As cigarette smoking declines and e-cigarette use becomes more common, understanding the health profiles of people who smoke, vape, use both products, or have quit smoking has become increasingly important.

But there is a major problem in much of the existing research: people who use e-cigarettes are often treated as a single group, even though many are former smokers.

That distinction matters.

In our new study, published in the Journal of Epidemiology and Population Health, we examined how smoking, vaping and dual use are associated with chronic disease and multimorbidity among adults in England, while separating people who vape according to whether they had previously smoked cigarettes.

Why smoking history matters when studying vaping and health

Many adults who currently use e-cigarettes previously smoked combustible cigarettes. Because cigarette smoking is strongly associated with chronic disease, failing to account for previous smoking can make it difficult to interpret health differences observed among people who vape.

For example, if a person develops a smoking-related health condition and later switches completely from cigarettes to e-cigarettes, a cross-sectional study may observe both vaping and disease at the same time. That does not mean vaping caused the disease.

Our study therefore examined six distinct nicotine-use groups rather than simply comparing “smokers”, “vapers” and “non-users”.

What did the study examine?

We analysed data from 7,625 adults aged 16 years and older who participated in the Health Survey for England 2022.

Participants were classified as:

• never users of nicotine products;
• exclusive cigarette smokers;
• former cigarette smokers;
• current e-cigarette users who had never smoked;
• current e-cigarette users who had previously smoked; and
• dual users of cigarettes and e-cigarettes.

We examined seven groups of long-standing health conditions, including mental health, respiratory, cardiovascular, musculoskeletal, digestive, nervous system, and endocrine or metabolic conditions.

We also assessed overall chronic disease burden and multimorbidity, meaning the presence of multiple long-standing health conditions.

What did we find?

Compared with people who had never used nicotine products, several groups had higher adjusted odds of reporting at least one long-standing health condition.

The adjusted odds were higher among:

• exclusive cigarette smokers;
• former smokers;
• current e-cigarette users with a history of smoking; and
• dual users of cigarettes and e-cigarettes.

A similar pattern was seen for multimorbidity.

Dual users had more than twice the adjusted odds of being in a higher multimorbidity category compared with never users, while current e-cigarette users who had previously smoked also had elevated odds.

The most consistent disease-specific differences were seen for mental health, respiratory and musculoskeletal conditions.

For example, dual users had particularly high adjusted odds of mental health conditions, while exclusive cigarette smokers, former smokers and dual users had higher odds of respiratory conditions.

What about people who vape but have never smoked?

This is where interpretation becomes especially important.

Among current e-cigarette users who had never smoked cigarettes, we did not find clear adjusted evidence of higher overall morbidity or multimorbidity compared with never users.

However, this should not be interpreted as evidence that vaping is harmless.

Only 44 participants in the study were current e-cigarette users who had never smoked, and most were young adults. The estimates for this group were therefore imprecise, with wide confidence intervals.

Many chronic diseases also develop over years or decades. Younger adults who have only recently started vaping may not yet have had sufficient exposure or follow-up time for long-latency conditions to emerge.

Larger longitudinal studies are needed.

Why cross-sectional studies require caution

Our study used cross-sectional data, meaning nicotine-use status and health conditions were measured at the same point in time.

Because of this, we cannot determine which came first.

For former smokers, poorer health may have encouraged smoking cessation. Similarly, some people with existing illness may have switched from cigarettes to e-cigarettes or begun using both products.

This phenomenon, sometimes called health-related switching or illness-induced quitting, is one reason smoking history must be considered when studying vaping and chronic disease.

The results therefore describe differences in health profiles across nicotine-use groups. They do not prove that a particular product caused the observed conditions.

What are the public health implications?

The main message is simple: not all e-cigarette users have the same exposure history.

Combining people who previously smoked with people who have never smoked can obscure important differences and may lead to misleading conclusions about vaping and health.

Researchers studying the long-term health effects of e-cigarettes should account carefully for previous cigarette smoking, smoking duration, smoking intensity and time since quitting.

From a tobacco-control perspective, the findings also reinforce the importance of moving people completely away from combustible cigarettes rather than maintaining long-term dual use.

Smoking remains a major contributor to chronic disease, and continued cigarette exposure is likely to remain a key driver of poor health among many current nicotine users.

As nicotine-use patterns continue to change, better longitudinal evidence will be essential to separate the health consequences of current vaping from the accumulated effects of past smoking.

The study, “Heterogeneous associations between cigarette and e-cigarette use patterns and chronic disease burden: A population-based study,” is published in the Journal of Epidemiology and Population Health.

Yusuff Adebayo Adebisi

Pharmacist and epidemiologist advancing equity-driven, policy-relevant public health research. PhD Researcher at the University of Glasgow. Director of Research at Global Health Focus.

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