Discussion
We have focused our analysis on office-based primary care practices rather than on larger hospital networks or academic medical centres. The reasons for this are twofold. First, office-based practices serve a greater proportion of the population. Specifically, CDC data from 2012 showed that the volume of office-based visits is about 7.4 times that of hospital visits.5 Second, we anticipate that office-based practices may need additional or different support to become self-sustainable in the use of CDSS, as many of them are under-resourced.
Interpretation of the study results
This paper presents the results of secondary data analysis from a CDC nationwide survey on ambulatory medical care visits, NAMCS. We notice that the survey does not contain a single question regarding CDSS availability and usage. Further, CDSS availability and usage data in primary care settings also are not readily available in the ONC Health IT Dashboard, despite the rich data reported for Meaningful Use. CDSS availability and usage data are critical benchmarks to further identify the true impacts of CDSS in primary care settings. Such data can provide key evidence to estimate the scale of CDSS use and impacts for health IT-related policymaking as well.
The analysis indicates that CDSSs in primary care settings are highly available (71.8% to 100%) and are used routinely (68.5%–100%) when EMR/EHR are used in both solo and non-solo practices. The rates are slightly lower in solo practices when they are entirely EMR/EHR based. Solo practices, however, have a significantly lower overall EMR/EHR rate (59.3% vs 86.4%, p<0.001). Therefore, CDSS usage rates are significantly lower (the differences range from 16.3% to 28.9%) for every measure in solo primary care practices than in non-solo settings without considering their EMR/EHR status. Without a carefully planned investigation, we can only speculate on the reasons (eg, lack of in-house technical support, physicians’ experience and types of EHR systems) for such large differences. The lower availability and usage rates in solo primary care practices suggest that greater investment in the entire life cycle of CDSS, longer time of investment or more user-friendly technology may be necessary to improve CDSS use by this group of practitioners.
Noticeably, about 40% of solo practices do not use EMR/EHR completely, and 23.7% (table 1) of solo practices do not have EMR/EHR at all. Meanwhile, the office-based practices’ general EMR/EHR adoption rate reached 86.9% in 2015. The data show a clear inequity in EMR/EHR adoption in solo practices, even under the US government incentive programme ‘Meaningful Use’. The data also support our hypothesis that small practices, especially solo practices, may need additional support on top of the initial incentives to adopt EMR/EHR, but also support on the use of EMR/EHR continuously and, further, CDSS use on a consistent basis.
When the practices are entirely EMR/EHR based, EREMIND, which provides reminders for interventions or screening tests, is the only variable that solo practices used significantly higher than did non-solo practices. This result shows the true potential of basic CDSS functions in primary care operations, such as reminders. If the CDSS function is useful and the application is straightforward, it will be used frequently at the point of care.
The capability to automatically generate graphs for lab results (ie, EGRAPH) has the lowest availability in non-solo practices and solo practices (78.1% and 71.8%, respectively) and lowest usage rates (77.3% and 68.5%, respectively) when they are entirely EMR/EHR based. The general use rates of automatic graph generation for lab results (ie, EGRAPH) are 73.6% (non-solo) and 44.7% (solo), without considering their EMR/EHR status. The second-lowest availability and usage rates are seen in the capability to identify patients for preventive or follow-up care (ie, EIDPT) in both groups. Although the value of prevention is well recognised, only 12.7%–82.9% of the population receives recommended prevention services.10 A CDSS in primary care settings has the potential to facilitate preventive services2 for the majority of the population. Although we do not have evidence to explain exactly why the use of the EGRAPH and EIDPT is significantly lower in solo practices, we feel that the reason may relate to the following factors: whether the configuration of using EGRAPH and EIDPT is difficult, whether it takes more cognitive power to interpret the generated graphs, or whether the results generated by EGRAPH and EIDPT can be used by primary care providers directly in clinical encounters.
Our original research interest is CDSS usage by primary care physicians in small practices (practices with less than five physicians), for whom both EHR and CDSS are relatively new. According to a 2018 physician survey in the USA, 36.9% (2018 data) of physicians are in primary care.11 About 16.5% of physicians work in a solo practice (2017 data) and 22.3% of physicians work in a two-to-four physician practice (2016 data).11 12 Thus, about 40% of primary care physicians work in small practices, and about 15% of the physicians work as primary care providers in small practices. Considering the possible resource restraints in small practices versus large academic centres or large healthcare systems, these relatively new EHR and CDSS adopters and users may need some health IT support, as it is unlikely there is in-house IT support within these practices. To determine the CDSS usage rate baseline is the first concern that we would like to address, which will set the benchmark for further studies. In the NAMCS dataset, however, only solo and non-solo practice types are collected; therefore, we compared solo and non-solo practices. In addition to the types of practices and the ownership of practices that we used in our analysis, there are other characteristics that may be used to stratify the dataset, for example, payment type (eg, Medicare and Medicaid) and patients’ characteristics.
Significance of using CDSS in clinical practice
CDSS has been used to deliver safer care13 and consistent preventive services as well as to improve chronic condition management.1 2 Using a CDSS in office-based primary care practices can be a critical factor to improve population health, increase preventive services and control ever-growing healthcare expenses.
For example, one of the most commonly reported medical errors made by family medicine physicians in the USA and in other countries concerns prescription medications,14–16 which can be reduced by incorporating and using drug–drug and drug–allergy interaction CDSSs. The ability of a CDSS to capture patients’ medications and allergies is a critical foundation for identifying potential drug–drug and drug–allergy interactions. These features have the highest usage rates in both non-solo primary care practices (about 100%) and solo primary care practices (about 99.4%), if they are entirely EMR/EHR based, suggesting that further implementation of such a CDSS on a larger scale is feasible and likely warranted.
The rules of a CDSS, human and machine-readable, decide a CDSS’s performance within clinical contexts. CDSS rules must be maintained continuously to ensure the full potential of a CDSS over time. Outdated rules can lead to missing alerts about preventive services or follow-up appointments or even to a patient’s death due to outdated drug interaction alerts. Considering the relatively high CDSS usage rates, we envision that CDSS rule management and maintenance will be vital to ensuring that CDSS perform continuously as expected.
CDSS rule management and maintenance have been recognised as challenging in large institutions,4 17–19 which usually have in-house technical support and adequate resources. Thus, we anticipate that CDSS rule management and maintenance will be one of the greatest challenges to increased use in office-based settings, especially in solo practices. Data on the current state of CDSS in these settings will help to estimate the scale of CDSS rule management and maintenance that such settings will need.
Limitations of the study
One limitation of our analysis is that usage data answer only the question of whether the CDSS functionality was used, but do not tell whether the CDSS is used to validate or facilitate the development of, or change physicians’ clinical decisions. Another limitation is that the reported CDSS use focuses on traditional definitions of a CDSS. It is possible that providers also may be using clinical guidelines or proprietary or publicly accessible online resources as a CDSS within their EHR systems. Therefore, the actual use of a CDSS may be much higher than what is reflected in this paper.
Another limitation of this study is that we selected available measures as representatives of CDSS from NAMCS 2015, which is a small portion of CDSS, not comprehensive coverage of CDSS. In addition, preventive alerts are on the administrative side of medical care delivery, not as sophisticated as a true medical decision. We do recognise that CDSS can include a large range of functionalities, from basic preventive reminders, such as those we used in this paper, to the advanced decision support tools, such as those facilitated by deep learning algorithms. Therefore, any further interpretation of our results should be within the context.
Implications of the study and future work
Our results provide strong evidence that CDSS, especially under the categories of basic preventive reminders and drug interaction alerts, is used routinely in primary care practices if the practices are entirely EMR/EHR based, with rates of routine usage that range from 68.5% to 100%. When classified according to practice type, solo practices have significantly lower usage rates on several measures if practices are entirely EMR/EHR based. Solo practices have significantly lower usage rates on every measure without considering practices’ EMR/EHR status. Investment in more user-friendly technologies may be necessary to bring solo practices up to speed in exploring the full potential of a CDSS in clinical care.
Although our data were collected in the USA, we do feel such results can be used as an important reference point and benchmark for international peers to compare the CDSS usage across different countries, especially considering that although USA is a high-income county, its health system is fundamentally different from those of most other high-income countries. Whether such difference plays a role in CDSS usage behaviours, our analysis results provide baseline data for further investigations.
One future research direction is to explore the possibilities to enable primary care providers, especially the ones who work in office-based settings, to manage and maintain CDSS rules independently. Many such practices, especially solo ones, are under-resourced, which is indicated by the lower EMR/EHR adoption rates and lower CDSS usage rates in solo primary care practices. Under-resourced practices are unlikely to allocate additional resources for maintenance of CDSS rules, even though it is necessary to keep CDSS rules updated regularly. Therefore, development of straightforward and user-friendly tools to enable primary care providers to maintain the CDSS rules independently can be a promising solution.
