A Taxonomic Integrative Review of Short Message Service (SMS) Methodology

Abstract

Background: To acquire self-management skills that affect clinical outcomes, collaboration and communication with one’s health care team is essential, yet many health care systems are not designed adequately to be responsive to a patient’s efforts to self-manage. This review synthesizes the intervention methodology of current studies facilitating the efforts of health care providers who wish to design, develop, and implement evidence-based SMS programs for patients with diabetes, focusing on clinical outcomes of A1C values, medication adherence rates, and participant satisfaction. Methods: This integrative review was conducted using an integrative taxonomic analysis approach. This approach involves creating a classification system with domains or characteristics, defining the relationships between those domains, and creating a foundation for new theories or constructs. Results: Synthesis of the evidence included in this integrated review suggests the best design for a SMS diabetes management program aimed at improving A1C levels, medication adherence rates, and participant satisfaction is an intervention providing weekly SMS education, with 2-way message direction, that is 3 months in length. Conclusions: The studies in this review have demonstrated that SMS interventions can be an important part of a viable and effective program in the effort to better manage adults with type 2 diabetes.

The chronic disease of diabetes, a progressive endocrine disorder, dramatically impacts American health care systems, communities, families, and individuals by its prevalence, morbidity, complications, as well as financial and economic burdens. The Center for Disease Control (CDC), in its National Diabetes Statistics Report 2014,¹ reports 28.9 million Americans 20 years or older have diabetes; an estimated 8.1 million of those Americans are currently undiagnosed. In addition, 86 million more Americans have prediabetes.¹ With the staggering prevalence of diabetes comes the presence of comorbidities and complications.

Primary care providers (PCPs), who account for approximately 90% of diabetic care delivery in the United States,² are responsible for facilitating a comprehensive treatment plan that follows evidence-based standards of care. However, health care systems are peppered with barriers to effective and comprehensive chronic care (eg, time constraints, resource availability, access to care, and financial support), shifting their focus of care to disease exacerbations and acute illness and away from prevention, maintenance, and disease self-management education, potentially explaining why only 1 in 8 American patients meets their target blood pressure, lipids, or plasma glucose readings.³

To acquire self-management skills that affect clinical outcomes, collaboration and communication with one’s health care team is essential, yet many health care systems are not designed adequately to be responsive to a patient’s efforts to self-manage.⁴ The Health Information Technology for Economic and Clinical Health Act of 2009 includes financial provisions for the development and implementation of electronic health record (EHR) provider incentive programs, administered by the Center for Medicare and Medicaid Services, known as “meaningful use.”⁵ This incentive program requires—for reimbursement—that health care systems integrate technology such as EHR, decision support guidelines, and patient portals, which allow for EHR-connected, secure short message service (SMS) communication between health care teams and patients.

Short Message Service

The employ of SMS as a communication platform is a method of providing health care with an immediate, asynchronous, customizable, and widely adopted innovation.⁶ Society has implemented short messaging into its daily routine to accomplish tasks such as reminding a teenager to be home by curfew, requesting a gallon of milk on the way home from work, setting a meeting at a particular location, or conveying a heartfelt sentiment to a distant relative. According to the Pew Research Center, by spring 2011 Americans were sending an average 40 text messages per day, supporting that adoption of SMS as a communication tool between patient and provider is likely.⁷

The purpose of this integrative review (IR) is to synthesize findings of current studies about SMS intervention methodology used in the management of adult patients with diabetes type 2, focusing on the effect SMS characteristics have on clinical outcomes of A1C values, medication adherence rates, and participant satisfaction.

Methods

Design

This IR was conducted using an integrative taxonomic analysis approach. This approach involves creating a classification system with domains or characteristics, defining the relationships between those domains, and creating a foundation for new theories or constructs.⁸ IRs allow for the inclusion of experimental and nonexperimental research, which provides a comprehensive understanding of topics that affect health care and policy.⁹

Data Source

A comprehensive search of the academic electronic databases CINAHL and MEDLINE was conducted seeking the best evidence on the use of SMS interventions in the education and management of diabetes. Guided by a hierarchal framework, seeking strongest evidence first, each database search was performed with the key terms “short message service” OR “SMS” AND “diabetes type 2” AND “diabetes education.” The method of citation chasing was also completed. Resources that met inclusion criteria were (1) written in English, (2) covered the target population of adults with diabetes type 2, (3) had a primary focus of short messaging interventions for diabetes management and education, (4) measured A1C, medication adherence, or patient preference as an outcome, (5) was published between 2008 and 2014, and (6) was published in peer-reviewed journals. Exclusion criteria were resources that did not discuss the SMS intervention methodology or were not about the management of diabetes.

The CINAHL and MEDLINE database search resulted in 25 potential resources. Five resources were eliminated for duplication on database results. An abstract review eliminated 11 resources due to not meeting inclusion criteria, or not being closely related to the objective of this review. An in-depth review eliminated 3 more resources due to lack of detail in the SMS intervention methodology, or outcomes measured did not include HgA1C, medication adherence, or patient preference (Figure 1). Six studies were chosen for this IR.^10-15

Figure 1.

Literature review process.

Study Strength and Design

The included studies were appraised for strength and quality using the Johns Hopkins Nursing Evidence-Based Practice Appraisal Tool for Research Publications.¹⁶ Evidence level determination of included studies follows Melnyk and Fineout-Overholt’s hierarchal pyramid.¹⁷ Evidence in this review consists of 2 RCT’s,^14,15 3 quasi-experimental studies,^11-13 and 1 qualitative study.¹⁰

Results

The 6 studies of this review focused on SMS intervention, with varied study length and intervention design. Five of the studies used 2-way messaging, allowing participants to respond to or request information from researchers.^10-13,15 The messages were generated by a computer server in 3 of the studies,^10,13,14 2 of which were driven by software designed by the researchers themselves.^10,13 The frequency of SMS communication varied across all studies ranging from 3-4 times a day,^10,13 to 1-3 times a week.^11,12,15 The length of the studies all varied as well, with the longest studies occurring over a 12-month period,^12,15 and the shortest lasting 4 weeks.¹⁰ Three of the studies measured medication adherence,^10,13,14 and 4 measured A1C values as a primary outcome.^11-13,15

SMS Intervention Methodology

The decision to implement knowledge into practice requires a review and analysis of the best available research looking at its relevance and potential impact on clinical practice.¹⁸ A potential barrier to SMS adoption by health systems is varying intervention methodology, and many reviews do not include intervention detail to guide implementation into practice. Utilizing a taxonomic approach, 3 SMS domains emerged in the studies of this review: (1) message frequency, (2) intervention length, and (3) message direction (see Figure 2). An effective intervention method emerged with comparison of the domains’ varied characteristics and their effect on the outcomes of A1C values, medication adherence, and participant satisfaction.

Figure 2.

SMS characteristics and HgA1C outcome.

Domain: Short Message Frequency

Studies in this review were conducted with either a once daily or weekly message format; however, frequency of SMS varied within each format due to 2-way design. Two of the studies, developed by the same researchers, followed a daily message format,^10,13 3 studies followed a weekly format,^11,12,15 and message frequency for the remaining study was determined by missed scheduled medication doses.¹⁴

Daily messaging over a 6-month time period resulted in an A1C level decrease of 0.7 (P = .01) from baseline.¹³ Three studies designed with a weekly SMS produced A1C reductions from baseline of −1.32 (P < .05),¹⁵ –2.75 (P = .001),¹¹ and −1.49 (P < .05).¹² This suggests that a weekly SMS design can produce a statistically significant reduction in A1C values with less resource consumption compared to daily SMS intervention. None of the studies in this review with a weekly SMS format examined medication adherence, making a domain comparison of SMS frequency and medication adherence impossible. Participant satisfaction with the use of SMS intervention was reported as 73%¹³ and 94%¹⁰ for daily SMS study designs, and 100%¹¹ for weekly study designs.

Domain: Length of Short Message Intervention

The length of SMS intervention varied from 4 weeks to 12 months. Two studies^12,15 were a 12-month design, but provided data at 3-month intervals, allowing for 3 comparison points; a third study¹¹ was a 3-month design. Comparison of the effect on A1C levels of the 3-¹¹ and 12-month^12,15 studies revealed the largest A1C level decrease in the first 3 months of intervention. The 12-month studies^12,15 showed a slight A1C increase at the 6-month point, and a slight decrease at the 12-month point. These findings suggest a 3-month design may be the most effective intervention length for the greatest A1C reduction (see Figure 2, Table 1). A fourth study,¹³ a 6-month design, did not have a 3-month AIC result, but showed an A1C reduction at its conclusion.

Table 1.

Domains and Characteristics of SMS and Outcomes.

	Outcomes
	HgA1C		Medication dose		Satisfaction
Message domains	Pre	Post	Pre	Post	Percentage
Message frequency
Daily	Nundy 7.9	7.2 (–0.7, P = .01)	Nundy 83%	91% (+8%, P = .003)	Nundy 73%
			Dick 1.9 missed/week	0.6 (–1.3, P = .003)	Dick 94%
Weekly	Yoon 8.09	6.77 (–1.32, P < .05)			Hussein 100%
	Hussein 9.66	6.91 (–2.75, P = .001)
	Kim 8.16	6.67 (–1.49, P < .05)
Program length
4 weeks			Dick 1.9 missed/week	0.6 (–1.3, P = .003)	Dick 94%
3 months	Yoon 8.09	6.94 (–1.15, P < .05)			Hussein 100%
	Hussein 9.66	6.91 (–2.75, P = .001)
	Kim 8.16	6.94 (–1.22, P < .05)
6 months	Nundy 7.9	7.2 (–0.7, P = .01)	Nundy 83%	91% (+8%, P = .003) (5%, P = .065)	Nundy 73%
	Yoon 8.09	7.04 (–1.05, P < .05)	Vervloet		Vervloet 75%
	Kim 8.16	7.07 (–1.09, P < .05)
12 months	Yoon 8.09	6.77 (–1.32, P < .05)
	Kim 8.16	6.67 (–1.49, P < .05)
Message direction
1-way			Vervloet	(5%, P = .065)	Vervloet 75%
2-way	Nundy 7.9	7.2 (–0.7, P = .01)	Nundy 83%	91% (+8%, P = .003)	Nundy 73%
	Yoon 8.09	6.77 (–1.32, P < .05)	Dick 1.9 missed/week	0.6 (–1.3, P = .003)	Dick 94%
	Hussein 9.66	6.91 (–2.75, P = .001)			Hussein 100%
	Kim 8.16	6.67 (–1.49, P < .05)

Three studies measured medication adherence, one 4-week¹⁰ and two 6-month^13,14 designs. The 4-week study¹³ had a baseline mean of 1.9 missed medication doses per week. The study concluded with a mean of 0.6 missed medication doses per week, a decrease of 1.3 doses per week (P = .003).¹³ The 6-month studies reported improvement in medication adherence by percentages, 1 reporting 5% fewer missed doses (P = .0365),¹⁴ and the other reporting a baseline medication adherence rate of 83%, improving to a poststudy adherence rate of 91% (P = .003).¹³ All 3 studies found an improvement in medication adherence without a standout domain characteristic. Thus, conclusions about most effective SMS intervention length for medication adherence are not appropriate (see Table 1).

Participant satisfaction was a measured outcome in studies with 4-week,¹³ 3-month,¹¹ and 6-month^13,14 study designs. Due to the high satisfaction rates of participants from all 3 study designs, it appears that the domain of SMS intervention length may not play a significant role in participant satisfaction (see Table 1).

Domain: Short Message Communication Direct

Study designs for message direction were either 1- or 2-way, distinguishing how communication is shared. In 1-way direction, communication originates from the researcher or a computer database without an option for participants to respond. In the 2-way direction, communication can originate from the researcher or computer database as well as the participant, with response capability by the receiving party. Five of the 6 studies included in this review involved a 2-way design.^10-13,15

Four studies measured A1C level as a primary outcome, all of which used 2-way communication^11-13,15 (see Figure 2). The study using 1-way communication did not measure A1C levels.¹⁴ The studies measuring A1C levels had decreases from baseline values, 3 reporting statistical significance. A1C reductions were −1.32 (P < .05),¹⁵ –2.75 (P = .001),¹¹ –1.49 (P < .05),¹² and −0.7 (P = .01).¹³ Studies designed with 2-way SMS direction have produced reductions in A1C levels; however, conclusions about SMS direction cannot be made without comparison to studies that used 1-way SMS direction.

Three studies measured medication adherence; 2 used a 2-way communication direction,^10,13 and 1 used a 1-way direction.¹⁴ The study using 1-way direction measured missed medication doses with the use of a real-time medication monitoring (RTMM) device. If a participant failed to open the medication dispensing device at preprogrammed times, the device sent a signal to a computer server which responded with a SMS reminder to the participant to take the medication. The device recorded the time from the missed dose signal to dispensing of the medication. The control group had the RTMM device without a responding SMS intervention. The study found 5% fewer missed doses compared to the control group, as a result (P = .065).¹⁴ The studies utilizing 2-way communication used education and awareness to improve medication adherence, and allowed participants to ask questions regarding their medications or other diabetic issues by sending messages to researchers.^10,13 Both studies reported adherence improvements with results of 1.3 fewer missed doses per week (P = .003),¹⁰ and 8% improvement in medication adherence (83% baseline medication adherence to 91% adherence rate poststudy, P = .003).¹³ Medication adherence improved with both 1- and 2-way study designs; however, the 2-way designs produced statistically significant results, whereas the 1-way design produced positive results without statistical significance.¹⁰ This suggests that for the domain of SMS direction, the 2-way design may be more effective.

Participant satisfaction was a measured outcome for 3 two-way^10,11,13 and 1 one-way¹⁴ communication direction. Table 1 shows participants from both study designs were satisfied overall with the use of SMS interventions. Determination of which domain design produced the highest satisfaction may be best done with an analysis of the studies’ qualitative results. Participants from the study utilizing RTMM/SMS,¹⁴ a 1-way design, felt that they were supported in their medication management efforts because they had a “backup” if they forgot to take their medication. Participants from the studies using 2-way communication reported that they gained knowledge, had quick access to information, and felt supported by the ability to ask researchers questions, which increased their confidence in self-managing their diabetes.^10,11 A literature review about the barriers to diabetes management identified poor patient–provider communication and collaboration as a barrier to good self-care.¹⁹ SMS interventions with a 2-way design may provide both patients and providers with a communication platform that is the most effective in improving diabetes outcomes.

Discussion

The author of this review used an integrative taxonomic approach to examine the domains of SMS intervention. The domains emerged as (1) frequency, (2) intervention length, and (3) direction. The various designs are (1) daily or weekly SMS, (2) 4-week, 3-month, 6-month, or 12-month length, and (3) 1- or 2-way SMS communication direction.

The evidence supports weekly SMS frequency for the reduction of A1C levels. The studies using a weekly SMS design^11,12,15 demonstrated the most significant A1C reductions at the 3-month interval, but had an increase of those 3-month values at the 6-month point. The study using daily messaging¹³ had an A1C reduction at the 6-month point, but demonstrated less improvement than the studies that used weekly SMS (see Figure 2). Study results suggest that weekly SMS formats are more effective than daily for A1C reduction. One possible explanation is that participants may be more likely to value or reflect on information that is sent weekly, giving them time to seek clarification or information, before receiving new content. Daily frequencies may be too much information in too rapid of a sequence to allow for learning. A second possible explanation is resource exhaustion. Daily messaging may be too burdensome for health systems and participant’s alike, possibly diluting relevance and applicability, while challenging resources.

There were not adequate comparisons of daily and weekly designs to make a determination on best practice for medication adherence. Similarly, participants seemed satisfied with both intervention designs, which may be due to highly motivated participants, or because participants felt supported by all types of SMS intervention. Therefore, the most effective domain frequency based on A1C levels is a weekly SMS intervention.

This review examined SMS intervention lengths of 4 weeks,¹⁰ 3 months,¹¹ 6 months,¹⁰ and 12 months.^12,15 A1C levels were measured in the 3, 6, and 12-month designs. The 3-month point showed significant improvements in the 3-month study,¹¹ as well as the two 12-month studies.^12,15 The 6-month point showed an increase in A1C values from the 3-month measurement, but a decrease from baseline for both 12-month studies.^12,15 The 6-month study¹³ demonstrated an A1C reduction at the 6-month mark, but gave no measurement for the 3-month values. The 12-month studies continued to show A1C reduction at the 12-month mark, but had the most statistically significant A1C reduction by 3 months. One possible explanation for these results is that participants may have had the most to learn about their diabetes in the first 3 months of intervention, indicating information saturation. A second possible explanation is intervention exhaustion, signifying that 3-month intervals maximizes participant attention. This explanation and the findings of the studies support 3-month SMS intervention as the most effective for A1C reduction. However, further studies about education intervals or refresher courses may be indicated.

The evidence supported improved medication adherence in the 4-week and 6-month designs; however, there were no 3- or 12-month designs that measured medication adherence, making a true comparison of SMS intervention length for medication adherence effectiveness impossible. Participant satisfaction was measured in a 4-week, 3-month, and 6-month design. Participants were generally satisfied with SMS intervention in all intervention lengths. The most effective domain length, based on outcome measurements of A1C levels is a 3-month design. There was not sufficient data to make a conclusion of best intervention length for medication adherence and participation satisfaction.

SMS direction was also compared in this review. Studies^11-13,15 that measured A1C levels were 2-way communication, and all demonstrated significant A1C reductions. There were no 1-way communication studies that measured A1C outcomes, making a true comparison impossible. There were studies with both directions that measured medication adherence. The study using 1-way communication¹⁴ reported fewer missed medication doses, but was not statistically significant. The 2-way direction studies^10,13 reported statistically significant improvements in medication adherence rates. One-way communication may not be an effective way of learning the ramifications of medication adherence. Two-way communication allows for the participant to be a part of their health care decisions while benefiting from the support of their health care team.

Participant satisfaction was generally positive in both intervention designs. Satisfaction surveys revealed that participants from the 2-way directed studies felt supported in their decision making, and felt increased confidence¹⁰ to self-manage their diabetes. Participants also stated that they liked having a source of information¹¹ to go to when making medication, dietary, or lifestyle changes. Surveys from the 1-way directed study using the RTMM¹⁴ indicated that they liked having a backup if they forgot their medication. Based on overall participant satisfaction with SMS intervention, both communication directions are effective. Therefore, overall, the most effective SMS communication direction based on A1C improvements, medication adherence improvement, and participant feedback is 2-way communication.

Synthesis of the evidence included in this integrated review suggests the best design for a SMS diabetes management program aimed at improving A1C levels, medication adherence rates, and participant satisfaction, is an intervention providing weekly SMS education, with 2-way message direction, that is 3 months in length.

This review has several limitations. There is a paucity of research that describes intervention methodology in comparable formats, making conclusions difficult. The positive findings may be attributed to the high motivation level of participants who have chosen to participate, although we can always attribute disease management success to patient motivation or desire to be well.

Future implications would be to study the 3-month, 2-way direction, weekly communication SMS intervention design repeatedly, and then determine if behavioral and clinical improvements are sustained at postintervention intervals, or if refresher programs would be beneficial.

Conclusion

The studies in this review have demonstrated that SMS interventions can be an important part of a viable and effective program in the effort to better manage adults with type 2 diabetes. This review synthesizes the intervention methodology of current studies facilitating the efforts of health care providers who wish to design, develop, and implement evidence-based SMS programs for patients with diabetes. Innovative delivery platforms have been delivered to the door of health care systems via government initiated programs. Health care systems should capitalize on the potential to change how we deliver much needed information to our patients and change their engagement with health care from being a destination where they arrive once every 3 months to a way of life.