PICO SEARCH ASSIGNMENT WORKSHEET              

Brief description of patient problem/setting (summarize the case very briefly):

Patient is a 60 year old male with a past medical history of type 2 diabetes mellitus, hypertension, hyperlipidemia, stent placement with CAD who presents to the office today for diabetes care management. The original intent of his visit was to review his glucose readings to assess his glycemic control, however the patient has not been compliant with instructions and has not been recording his readings.

Search Question: Clearly state the question (including outcomes or criteria to be tracked) 

In adults with diabetes, does continuous glucose monitoring compared with self-monitoring of blood glucose improve glycemic control?

Question Type: What kind of question is this? (boxes now checkable in Word) 

☐Prevalence        Screening                    Diagnosis 

☐Prognosis                             XTreatment                ☐Harms 

Assuming that the highest level of evidence to answer your question will be meta-analysis or systematic review, what other types of study might you include if these are not available (or if there is a much more current study of another type)?  

Please explain your choices.  

If both meta-analyses & systematic reviews were not available to answer my question I would consider randomized controlled trials as my next option. RCT’s are valuable studies when looking to directly compare two types of interventions and because they are randomized, they help to reduce selection bias and confounding that can affect the results. They are especially useful in this comparison because outcomes such as HbA1c and hypoglycemic episodes can be measured objectively between both groups of patients. Furthermore, RCT’s in this setting present no major ethical concerns as it relates to assigning patients to either monitoring method since both are acceptable approaches to diabetes management.

If randomized controlled trials were not available, I would then consider prospective cohort studies. These studies are another valuable option because they can follow patients over time and compare outcomes in those using either monitoring method. They can also potentially help to identify patterns in terms of which patient populations benefit the most from CGM such as patients using insulin, those that have poor baseline glycemic control, or those at higher risk for hypoglycemia.

PICO search terms:

P	I	C	O
Adults with diabetes	Continuous glucose monitoring	Self-monitored blood glucose	Glucose control
Adults with type 2 diabetes	CGM	Fingerstick glucose monitoring	Hemoglobin A1c
Patients with diabetes mellitus	Glucose sensor monitoring	Blood glucose self-monitoring	HbA1c reduction
Adults with poorly controlled diabetes		Fingerstick testing	Hyperglycemic episodes
Type 2 diabetic patients			Mean glucose levels
			Glycemic control

Search tools and strategy used:

I used 3 different databases to search for evidence relevant to my PICO question including Pubmed, Google Scholar, and CINAHL. I developed my search strategy around the basic components of my PICO question to maintain relevancy in my search results. This was done to ensure that my search focused on studies comparing continuous glucose monitoring (CGM) with self-monitoring of blood glucose (SMBG) in adults with type 2 diabetes. For the population I used terms such as adults with diabetes, adults with type 2 diabetes, adults with poorly controlled diabetes etc. For the outcomes I search terms such as glycemic control and mean glucose levels which revealed very focused and relevant results. I also applied filters and limiters such as systematic review, review article and last 10 years in order to limit my results to high-level evidence that is also recent. I tried to prioritize head to head comparisons of CGM and SMBG in addition to systematic reviews and meta-analyses, I did also end up included an RCT as one of my 3 chosen studies. Overall, this strategy helped me to find enough relevant and high-quality evidence to establish a clinical bottom line.

Database	Search Terms Used	Number of Results	Filters/Limiters Applied
Pubmed	Adults with diabetes AND CGM OR fingerstick glucose monitoring AND glycemic control	15	Within last 10 years, Full text, Systematic review
CINAHL	Type 2 diabetics AND continuous glucose monitoring OR self-monitored blood glucose AND glucose control	29	In the last 10 years
Google Scholar	Type 2 diabetics AND continuous glucose monitoring OR self-monitored blood glucose AND glucose control	154	Review Articles

Results found: 

1. Janapala, Rajesh Naidu, et al. “Continuous Glucose Monitoring versus Self-Monitoring of Blood Glucose in Type 2 Diabetes Mellitus: A Systematic Review with Meta-Analysis.” Cureus, vol. 11, no. 9, 12 Sept. 2019, www.ncbi.nlm.nih.gov/pmc/articles/PMC6822918/, https://doi.org/10.7759/cureus.5634.

1. Study Type: Systematic Review & Meta-analysis
2. Abstract:

1. Background: Type 2 diabetes is highly prevalent and is associated with major microvascular and cardiovascular complications, making effective glycemic control important. However, intensive glycemic control can increase the risk of hypoglycemia, particularly in patients with longstanding disease. Continuous glucose monitoring has emerged as a potential alternative to self-monitoring of blood glucose because it provides frequent glucose readings and may improve diabetes management. The purpose of this review was to determine whether CGM is more effective than SMBG in patients with type 2 diabetes mellitus.
2. Methods: This study was a systematic review with meta-analysis. The authors conducted a structured literature search in MEDLINE (PubMed) using MeSH terms and keywords related to diabetes mellitus/type 2 diabetes, continuous glucose monitoring, self-monitoring of blood glucose, and outcomes such as HbA1c and hypoglycemia. Studies were included if they compared CGM with SMBG or routine glucose monitoring in adults with type 2 diabetes, reported HbA1c as an outcome, and had a baseline HbA1c of at least 6.5%. Pregnant women and inpatient populations were excluded. The primary outcome was the difference in mean HbA1c between the CGM and SMBG groups at the end of the studies. Heterogeneity was assessed with I², and pooled analysis was performed using RevMan 5.3.
3. Results: The search yielded 628 studies, of which six randomized controlled trials met inclusion criteria, and five RCTs were included in the final meta-analysis. These studies involved 374 total patients with type 2 diabetes: 186 in the CGM group and 188 in the SMBG group. Study duration ranged from 3 to 8 months, and the cumulative baseline mean HbA1c was 8.53%, suggesting generally poor glycemic control at baseline. The pooled analysis showed that CGM use was associated with a significant reduction in HbA1c compared with SMBG, with a pooled mean difference of -0.25% (95% CI -0.45 to -0.06; p = 0.01). Evidence regarding hypoglycemia and quality of life was mixed, with some studies showing benefit and others showing no significant difference.
4. Conclusions: This review concluded that CGM appears to be beneficial in patients with type 2 diabetes mellitus because it significantly reduces HbA1c compared with SMBG. The evidence suggests that CGM may also help with hypoglycemia detection and patient satisfaction, although findings for these outcomes were less consistent. However, the included studies were small and mostly short-term, so the authors noted that larger and longer randomized controlled trials are needed before broad generalizations can be made.
5. Key Points:

1. This is a systematic review and meta-analysis that compares continuous glucose monitoring (CGM) with self-monitoring of blood glucose (SMBG) in adults diagnosed with type 2 diabetes. In the process of conducting this review the authors reviewed randomized controlled trials and pooled data from five RCT’s representative of 374 patients.
2. The primary outcome that was examined was HbA1c reduction, this was used as the main determinant of glycemic control. Upon conducting the pooled analysis, they concluded that CGM was associated with a statistically significant reduction in HbA1c compared with SMBG, with a pooled mean difference of -0.25% (95% CI -0.45 to -0.06; p = 0.01).
3. In addition to HbA1c reduction, this study also reviewed other pertinent and clinically relevant outcomes such as hypoglycemia, glucose variability, time in range, and patient satisfaction. Overall, the evidence from these outcomes revealed mixed results. Some studies suggested that CGM may help detect hypoglycemia better especially nocturnal hypoglycemia and may improve satisfaction and lifestyle awareness in certain patients.
4. It is important to note that many of the participant had poorly controlled diabetes at baseline and this is evidenced by the fact that the baseline mean HbA1c across the included studies was 8.53%. This may indicate that CGM could be of most benefit in patients who are already not at goal.
5. There were several limitations discussed by the authors, for example it was explained that only Pubmed/MEDLINE was searched, the total number of included studies was small, and most studies were short in duration. The authors thus suggested that larger and longer-term randomized controlled trials are still necessary.

Why I chose this study:

• I chose this study because it offered a great comparison of the effects seen with type 2 diabetics using CGM and those using SMBG. It focused on glycemic control which was the outcome of focus for my PICO question, and it also mentioned other markers such as hypoglycemia, glucose variability, and patient satisfaction. It was also helpful that this study provided a clear pooled result demonstrating that CGM was associated with a modest but statistically significant improvement in HbA1c. It’s always helpful to have a pooled estimate because it’s a more clinically applicable estimate of effect as opposed to saying some studies favored CGM and some didn’t. Overall, I found it useful because it didn’t just focus on whether CGM was better butt instead it gave a balanced perspective considering all the available evidence.

4. Link to study: 

https://pmc.ncbi.nlm.nih.gov/articles/PMC6822918

2. Bergenstal, Richard M., et al. “Randomized Comparison of Self-Monitored Blood Glucose (BGM) versus Continuous Glucose Monitoring (CGM) Data to Optimize Glucose Control in Type 2 Diabetes.” Journal of Diabetes and Its Complications, vol. 36, no. 3, Mar. 2022, p. 108106, https://doi.org/10.1016/j.jdiacomp.2021.108106.

1. Study type: Randomized Controlled Trial
2. Abstract: 

1. Background: Type 2 diabetes is commonly monitored with hemoglobin A1c, with or without self-monitoring of blood glucose. However, A1c does not capture glucose variability or hypoglycemia, and standard blood glucose monitoring may miss important glucose excursions because it provides only intermittent readings. Continuous glucose monitoring offers more complete glucose data and may improve detection of hypoglycemia, time in range, and overall glucose patterns. Previous studies had not directly compared structured BGM with real-time CGM for their effect on glycemic control and hypoglycemia in adults with type 2 diabetes.
2. Objective: Evaluate whether structured BGM testing (BGM) or real-time CGM (CGM) lead to improved glucose control (A1c). Determine which approach optimized glucose control more effectively.
3. Methods: This study was a prospective, multi-arm parallel randomized controlled trial. Adults aged 18–75 years with uncontrolled type 2 diabetes (A1c ≥7.0%) treated with sulfonylureas, incretin-based therapy, or insulin with or without metformin were enrolled. After a baseline period with blinded CGM, 114 subjects were randomized to either structured BGM performed four times daily or real-time CGM used continuously for 16 weeks, with clinic visits every 4 weeks and medication adjustments based on glucose data and point-of-care A1c. The primary outcome was change in A1c, and secondary outcomes included time in range, glucose variability, hyperglycemia, and hypoglycemia.
4. Results: A1c means decreased from 8.19 to 7.07 (1.12% difference) with CGM (n = 59) and 7.85 to 7.03 (0.82% difference) with BGM (n = 55) (p < 0.001). BGM and CGM groups showed significant improvements in time in range and glucose variability—with no significant difference between the two groups. Clinically important hypoglycemia (<50 mg/dL) was significantly reduced for the CGM group compared with BGM (p < 0.01), particularly in subjects taking insulin or therapies with higher hypoglycemic risk (SU).
5. Conclusion: In T2D, structured, consistent use of glucose data regardless of device (structured BGM or CGM) leads to improvements in A1c control. CGM is more effective than BGM in minimizing hypoglycemia particularly for those using higher hypoglycemic risk therapies.
6. Key points: 

1. This study is a randomized controlled trial that directly compared SBGM and CGM in adults with type 2 diabetes. A total of 114 participants were randomized and then were followed over the course of 16 weeks.
2. Interestingly, the study found that both groups in fact improved their HbA1c which is a very positive finding. It suggests that consistent monitoring of glucose parameters regardless of the method or device ultimately leads to improved glycemic control in conjunction with treatment adjustments. However again the CGM group proved to be the biggest beneficiaries as they demonstrated reductions in A1c of 8.19% to 7.07% meanwhile the BGM group improved from 7.85% to 7.03%.
3. Despite both groups demonstrating improvements, the difference in A1c reduction between CGM and BGM was not found to be statistically significant. This represents an important finding because it shows that CGM was not clearly superior to structured BGM for lowering A1c alone based on the results from this study.
4. Although hypoglycemia is not a primary outcome for my PICO question, an important difference was found in this parameter. CGM was found to be more effective than BGM in reducing clinically important hypoglycemia particularly in patients using insulin or sulfonylureas which are both therapies associated with a higher risk of low blood sugar.
5. Additional improvements were demonstrated amongst both groups in terms of time in range, hyperglycemia, and glucose variability however CGM provided more complete glucose information. It also appeared to be especially helpful in identifying patterns surrounding mealtimes such as pre-meal drops and post-prandial peaks which are not as well detected by fingersticks.
6. Why I chose this study: 

• I chose this study because it was another balanced and fairly structured assessment of the efficacy of CGM compared to BGM. I took interest in the fact that the authors specifically compared structured BGM and not just random or infrequent fingersticks with CGM. What makes this so important is that it makes the comparison a lot more meaningful and fairer. Furthermore, this study demonstrates that the strength of a monitoring method is heavily dependent on the patient’s treatment regimen and their overall clinical risk. The authors also made some good points and highlighted key information as to why it’s important to not rely on HbA1c alone. They emphasized that HbA1v is only a reflection of an average and it can overshadow variability and fluctuations in glucose. As a result, two patients may have the same A1c, but their actual level of glycemic stability can vary greatly.

5. Link to study: 

https://www-sciencedirect-com.york.ezproxy.cuny.edu/science/article/pii/S1056872721003305?via%3Dihub

3. Lian, Xia, et al. “Impact of Real-Time Continuous Glucose Monitoring on Glycaemic Control in Adults with Type 2 Diabetes: Systematic Review and Meta-Analysis.” Frontiers in Endocrinology, vol. 16, 23 Jan. 2026, https://doi.org/10.3389/fendo.2025.1761579.

1. Study Type: Systematic review & Meta-analysis
2. Abstract:

1. Background: Real-time continuous glucose monitoring (rtCGM) may overcome important limitations of self-monitoring of blood glucose (SMBG), including missed glucose fluctuations, lack of trend data, and inability of HbA1c alone to reflect day-to-day glycaemic variability. This study aimed to evaluate whether rtCGM improves glycaemic control compared with SMBG in adults with type 2 diabetes, while also examining cardiometabolic and patient-centered outcomes.
2. Objective: To evaluate the effectiveness of real-time continuous glucose monitoring compared with self-monitoring of blood glucose in adults with type 2 diabetes, focusing on glycaemic control, cardiometabolic outcomes, and patient-centered measures.
3. Methods: Randomized controlled trials published in English with study intervention period ≥12 weeks, which compared real-time continuous glucose monitoring with self-monitoring of blood glucose in adults with type 2 diabetes were included in this systematic review. Analyses were conducted using Review Manager version 9.6. Risk of bias was evaluated using the Cochrane risk-of-bias tool. The Grading of Recommendations Assessment, Development and Evaluations approach was used to assess certainty of evidence.
4. Results: This systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eleven studies which compared real-time continuous glucose monitoring (n=437) with self-monitoring of blood glucose (n=352) were included. Real-time continuous glucose monitoring use was associated with a significant reduction in HbA1c (mean difference=−0.20%), improved time-in-range (mean difference=7.41%), reduced time-above-range (mean difference=6.93%) and reduced time-below-range (mean difference=0.26%). Glucose variability was significantly lower (mean difference=-1.06%) and users demonstrated greater improvements in readiness for diabetes self-management (standardized mean difference=0.69). No significant differences were observed in cardiometabolic or psychosocial outcomes.
5. Conclusion: Real-time continuous glucose monitoring improves glycaemic control and self-management capacity compared with self-monitoring of blood glucose in adults with type 2 diabetes. These findings support the integration of real-time continuous glucose monitoring into routine clinical care, particularly for individuals requiring intensive glucose monitoring and tailored self-care support.
6. Key Points:

1. This study is a systematic review and meta-analysis of randomized controlled trials that examined the impact of real-time continuous glucose monitoring (rtCGM) compared with self-monitoring of blood glucose (SMBG) in adults with type 2 diabetes. It included 11 total studies representing 789 participants overall.
2. Like my PICO question, the primary outcome was HbA1c with the pooled analysis showing that rtCGM was associated with a statistically significant reduction in HbA1c compared with SMBG. The mean difference was -0.20% which is modest, however it still overall suggests that rtCGM may provide a measurable benefit in glycemic control.
3. Like the other studies another finding was that rtCGM improved several CGM-derived glucose metrics beyond HbA1c. For example, it increased time in range by 7.41%, reduced time above range by 6.93% and time below range by .26% and it lowered glucose variability. This overall suggests that rtCGM may provide a more complete picture of glycemic control than HbA1c alone.
4. Interestingly, the study found benefits related to self-management as rtCGM users showed greater improvement in their readiness for diabetes self-management and performed fewer daily fingerstick checks. Despite this, there were no significant differences in cardiometabolic outcomes such as their weight, BMI, lipid profile, or blood pressure. Additionally, psychosocial outcomes such as treatment satisfaction and quality of life were also either mixed or not significantly different.
5. It was also recognized by the authors that the HbA1c reduction was found to be statistically significant, but it did not reach the 0.5% threshold that is often considered clinically meaningful by some guidelines. Limitations that were addressed included the fact they excluded non-english studies, and the data was limited in terms of addressing severe hypoglycemia and long-term complications.
6. Why I chose this study:

• I chose this study because while of course it answers my PICO question it goes beyond that by comprehensively evaluating both clinical and behavioral outcomes of rtCGM compared with SMBG. The authors also strongly emphasized that this study was among the first to evaluate not just clinical but also behavioral outcomes of rtCGM compared with SMBG. They measured outcomes such as self-management readiness, treatment satisfaction, quality of life, diet, and physical activity. It essentially rounds out the discussion and recognized that diabetes control is not fully captured by HbA1c alone as it helps patients to understand their day-to-day glucose patterns.

5. Link to study: https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1761579/full

What is the clinical “bottom line” derived from these articles in answer to your question? 

Based on the overall findings from these articles, the clinical bottom line is that CGM and especially real-time CGM appears to provide an overall modest but clinically meaningful advantage over self-monitoring of blood glucose in adults with type 2 diabetes. This advantage is most pronounced however when glycemic control is not just limited to HbA1c alone. The evidence does indeed support improved HbA1c but again the greatest benefits are seen when comprehensively evaluating a patient in terms of their time in range and above range, glucose variability, and episodes of hypoglycemia.

As stated, patients utilizing CGM were found to have an overall better display of daily glucose control. The Janapala et al. systematic review and meta-analysis found that CGM significantly reduced HbA1c compared to SMBG with a pooled mean difference of -0.25%. We also saw in the Lian et al. study a very similar conclusion because a pooled HbA1c reduction of -0.20% was found with rtCGM compared to SMBG. Among these benefits were a host of other benefits including time in rage (+7.41%), time above range (-6.93%), time below range (-0.26%), and glucose variability (-1.06%). This strongly demonstrates that CGM offers stabilization to its users in terms of day-to-day glucose management. The Bergenstal et al. study however provided a bit of nuance to the discussion. They found that structured BGM and CGM significantly improved A1c and the observed difference between groups was not statistically significant for A1c lowering alone. Instead CGM was found to be more effective at reducing episodes of hypoglycemia in patients on higher-risk regimens involving the use of insulin or sulfonylureas for example.

In consideration of all these points, CGM seems to offer the greatest clinical value when the goal of care is not just to lower HbA1c but to also improve day to day control and reduce the risks of hypoglycemia. However, the evidence does not point toward the dismissal of SMBG which if done in a structured and disciplined way can also provide benefits in glycemic control. Both have their role in glucose management, but CGM provides a more detailed perspective on glucose data which is very useful in patients with poorly controlled type 2 diabetes, those using insulin or sulfonylureas, and those that can benefit from closer monitoring of their trends and fluctuations.