Lifestyle-focused health reminders sent by text message to patients with coronary heart disease (CHD) helped increase their physical activity and lower their LDL cholesterol, systolic blood pressure, smoking, and body mass index in a recent study.
The researchers randomized 710 adult patients with CHD to either a control group that received usual care (n=358) or an intervention group that received 4 weekly text messages for 6 months in addition to usual care (n=352). Usual care generally included community follow-up, with the majority referred by their usual physicians to inpatient cardiac rehabilitation. The non-interactive text reminders provided advice and motivational support regarding healthy lifestyle changes and were adjusted to each participant’s baseline characteristics (i.e., a nonsmoker would not receive reminders about smoking cessation). Results appear in the Sept. 22/29 Journal of the American Medical Association.
At 6 months, levels of LDL cholesterol (the primary end point) were modestly but significantly lower in intervention participants (mean difference, −5 mg/dL; 95% CI, −9 to 0 mg/dL; P=0.04). The intervention group also saw reductions in systolic blood pressure (−7.6 mm Hg; 95% CI, −9.8 to −5.4 mm Hg; P<0.001) and BMI (−1.3 kg/m2; 95% CI, −1.6 to −0.9 kg/m2; P<0.001). The text messaging group also had significant increases in physical activity (293 metabolic equivalent of task minutes per week; 95% CI, 102 to 485 metabolic equivalent of task minutes per week; P=0.003) and a significant reduction in smoking (26% vs. 44%; relative risk, 0.61; 95% CI, 0.48 to 0.76; P<0.001).
In addition, the majority of intervention participants reported the text-message program to be useful (91%), easy to understand (97%), and appropriate in frequency (86%).The researchers bought a bulk package of text messages from a local service provider at a cost of less than $10 per patient, the study authors calculated, although they said it’s not clear whether the intervention represents a good value until formal cost-effectiveness analysis is conducted.
The authors noted several limitations, such as that patients were recruited at a large tertiary referral center and university teaching hospital in Sydney, Australia, and that patients who did not speak English or did not have a mobile phone were excluded, and therefore said that their results may not be generalizable.
These findings are consistent with existing yet limited evidence supporting the effectiveness of text messaging in changing health behaviors, the authors said. For the most part, this study had a larger sample size and longer follow-up time than similar studies conducted previously, according to the study authors.
Although the study demonstrates that mobile health interventions can influence behavior and improve risk profiles in the short term, the intervention was evaluated for only 6 months, and the durability of the observed benefits remains unknown, according to an accompanying editorial. The editorial also noted that some secondary outcomes, such as physical activity, were assessed by self-report, and patients were not blinded to their intervention status. “Integrating wearable devices that can passively monitor and objectively quantify outcomes like physical activity could minimize reporting bias in future studies,” the editorialists wrote.