Mobile phone support increases chances that people living with HIV will quit smoking

Smoking cessation support delivered via mobile phones increases chances that people living with HIV who smoke will quit, according to research published in the online edition of Clinical Infectious Diseases. Overall, people receiving mobile phone-based support were over two times more likely to stop smoking than people receiving the standard of care.

“The use of proactive cell phoned-based intervention that combined supportive counselling, motivational intervention and materials/topics targeted to PLWHA [people living with HIV] was successful compared to a usual care intervention that included physician advice to quit and tip sheets”, write the authors. However, absolute quit rates were low and the impact of the phone-based service diminished over time.

A team of Texan investigators was concerned about the high prevalence of smoking among people living with HIV, especially as smoking-related diseases are an increasingly important causes of serious illness and death in people with HIV. They therefore designed a study evaluating the efficacy of a mobile phone-based service to support people with HIV to stop smoking.

The research was conducted between early 2007 and late 2009 and involved 474 HIV-positive smokers who received care at the Thomas Street Health Center, Houston. All smoked five or more cigarettes a day and had an expired carbon monoxide level of 7ppm or above.

Participants were equally randomised into two study arms.

People in the control arm received current smoking cessation standard of care, including written information giving tips on how to quit as well as advice about how to obtain nicotine replacement therapy. People in the intervention arm were also provided with written information and access to nicotine replacement treatment. However, they also had access to smoking cessation counselling and a support “hot-line” via free mobile phones over a three-month period. This counselling used cognitive behaviour therapy and motivational interviewing techniques.

Smoking cessation was assessed after three, six and twelve months. Participants were asked if they had smoked during in the previous 24 hours, seven days or 30 days. Expelled carbon monoxide levels were also measured to verify smoking cessation.

Participants in the two study arms were well matched. Three-quarters were African American, 70% were men and their mean age was 45 years. Over a third had not completed high school and 79% were unemployed. There was a high prevalence of depression (67%) and the participants reported poor mental and physical functioning. Approximately 31% of participants were classified as having potentially harmful levels of alcohol consumption and 40% reported illicit drug use. The participants reporting smoking an average of 19 cigarettes each day.

The study retention rate was high, with three quarters of participants attending for the three-, six- and twelve-month follow-up visits.

The primary study outcome was cigarette abstinence in the seven days before the twelve-month follow-up interview. Results showed that telephone support was effective. People in the intervention arm were approximately two and a half times as likely to report not smoking in the previous week compared to individuals in the control group (OR = 2.41; 95% CI, 1.01-5.76). The intervention had a similar effect when the investigators examined the odds of not having smoked in the previous 24 hours or 30 days.

The treatment effect was strongest at the three-month follow-up point, when people in the intervention arm were four times more likely not to have smoked in the previous seven days compared to those in the control arm (OR = 4.3; p < 0.001).

However, the overall proportion of people who reported quitting was very low. The seven-day abstinence rate at three months was approximately 12% in the intervention arms and 3% in the control arm. The investigators attribute the low quit rate to the high prevalence of depression and the low uptake of nicotine replacement therapy.

To put this `quit rate` in context, a recent large trial showed that 30% of smokers who received nicotine replacement plus telephone support remained non-smokers after one year to 18 months.

The benefits of mobile phone support diminished over time. The investigators comment that the effect was “not well-sustained beyond the 3-month treatment period.” They conclude, “future studies will address sustaining the intervention effect, raising overall absolute quit rates, and reducing real-life barriers to smoking cessation.”