Background
The American Society of Echocardiography’s Committee on Pediatric Echocardiography Laboratory Productivity (C-PELP) was formed to study the organizational and productivity issues particular to academic pediatric echocardiography laboratories. After much deliberation, the committee chose studies per physician full-time equivalent per day –the average number of studies interpreted per day by a full-time echocardiography physician dedicated to the laboratory –as the primary measure of physician productivity.
Methods
A survey was sent to 74 North American pediatric echocardiography laboratory directors. The aims of the survey were to (1) determine the annual laboratory volume and types of echocardiographic studies performed, (2) define the average number of studies performed by a pediatric cardiac sonographer in a year, (3) assess the productivity of echocardiography physicians, and (4) identify factors (programmatic or laboratory related) that affect clinical productivity.
Results
There were 54 responses to the C-PELP 2011 survey. The average number of studies per physician full-time equivalent per day was 15.0 + 4.5 (median, 13.8; range, 6.2 -27.1), and the average number of studies performed per year by a sonographer was 1,297 + 326 (median, 1,279; range 717 -2,475). These figures were not adjusted for case complexity, time requirement for transesophageal echocardiography, level of expertise, or availability of sonographer assistance. Moreover, the issues of study quality and accuracy were not addressed.
Conclusions
The C-PELP 2011 survey gathered important information on the current organization and staffing of academic pediatric echocardiography laboratories, but the committee did not attempt to craft guidelines or recommendations on staffing requirements. The results of the survey, however, should provide a framework for additional investigation into the optimal structure and staffing of pediatric echocardiography laboratories.
The practical aspects of organizing and staffing an academic pediatric echocardiography laboratory have received little attention and have not undergone comprehensive evaluation at the national level. The clinical mission and, consequently, the organization of a pediatric echocardiography laboratory differ from that of an adult echocardiography laboratory because of the ages and diagnoses of the patients served. To address these organizational and productivity issues, the American Society of Echocardiography formed the Committee on Pediatric Echocardiography Laboratory Productivity (C-PELP). This group has focused its efforts on acquiring information on the current structure of academic pediatric echocardiography laboratories across the United States and Canada. Knowledge about laboratory structure and productivity will be vital as institutions address staffing in response to the evolving health care environment.
To obtain up-to-date information on pediatric echocardiography laboratory organization and productivity, the members of C-PELP sent a survey to North American pediatric echocardiography laboratory directors. The goal of the survey was to assess and understand the existing staffing structure and volume of echocardiographic studies performed and interpreted in academic pediatric echocardiography laboratories. Specifically, the survey aimed to (1) determine the annual laboratory volume and types of echocardiographic studies performed, (2) define the average number of studies performed by a pediatric cardiac sonographer in a year, (3) assess the productivity of echocardiography physicians, and (4) identify factors (programmatic or laboratory related) that affect clinical productivity.
Methods
The C-PELP 2011 survey was distributed to 74 academic pediatric echocardiography laboratories identified through a search for pediatric cardiology fellowship programs ( n = 46) and known contacts of laboratory directors ( n = 28). The survey was a digitally distributed questionnaire ( Appendix ) directed to pediatric echocardiography laboratory directors that sought to define laboratory and program size; physician staffing and work organization; sonographer staffing and duties; and specialized laboratory characteristics that might affect clinical productivity, including the availability of specialized testing, sedation, a fourth-year imaging fellow, and research personnel. It asked specific questions about laboratory volume of studies, laboratory staffing of physicians and sonographers, laboratory equipment, number of studies performed or interpreted by physicians and sonographers, physician assignment and dedicated coverage, protocols and personnel, physician weekend coverage, and sonographer assistance with transesophageal echocardiography (TEE) or fetal echocardiography. The centers were asked to report 12 months of recent data.
The number of physicians assigned to an echocardiography laboratory was calculated from responses to the question “How many echocardiography physicians are assigned to cover each modality each weekday?” The categories listed were (1) transthoracic echocardiography (TTE), (2) fetal echocardiography without other responsibilities, (3) fetal coverage as part of TTE coverage, (4) TEE without other responsibilities, and (5) TEE as part of TTE coverage. The number of full-time equivalent (FTE) physicians per laboratory needed to cover the daily clinical work was estimated for the respondents by adding up the number of nonoverlapping physicians in the five categories (i.e., if a lab had one physician cover TTE alone, one cover fetal echocardiography alone, and one cover TEE alone each day, that lab would require three FTEs per day, and if a lab had one physician cover TTE and TEE and another cover TTE and fetal echocardiography each day, it would require two FTEs per day). The annual number of studies per physician FTE was calculated by dividing the total number of studies in the surveyed year by the physician FTE for each laboratory. Finally, the number of studies per physician FTE per day was calculated by dividing studies per FTE by 250 business days per year. When physician coverage for a lab was unclear from the survey response and for all outliers after initial analysis, the laboratory director was contacted to clarify work distribution to more accurately estimate that laboratory’s daily FTE requirement.
The number of sonographers in a laboratory was calculated by adding the number of full-time pediatric sonographers (one FTE), defined as 35 to 40 hours/week dedicated to pediatric or fetal echocardiography, plus the number of part-time pediatric sonographers. The FTE value of a part-time pediatric sonographer was uniformly assigned as 0.4 (2 workdays per week) for analysis. The number of studies per sonographer was calculated by dividing the total number of studies in the surveyed year by the estimated number of sonographer FTEs per laboratory. Because of the method of calculation, the numbers of studies per sonographer were likely mildly inflated by including studies performed by attending physicians and fellows. Some laboratories had specific data on the number of studies per sonographer, and comparison of that information with survey-generated data correlated well (within approximately 15%). Therefore, the calculated numbers were used consistently for all laboratories. The number of studies per sonographer per day could be generated by dividing the annual number of studies by a typical number of workdays per year, but this analysis was not performed.
Results
Of the 74 academic pediatric echocardiography laboratories contacted, 54 (73%) completed the survey. The responding centers all reported 12 months of data, with 51 reporting on the 2010 calendar year and three using other fiscal year dates (one each starting July 2009, September 2009, and April 2010).
The characteristics of the 54 participating echocardiography laboratories are provided in Table 1 . As expected, most of the laboratories were large academic laboratories affiliated with training programs and moderate to very large surgical programs. The annual numbers of heart surgery cases at the responding institutions were <150 at four, 150 to 249 at 14, 250 to 349 at 12, and ≥350 at 24. One program operated in a group physician model without sonographers and thus was excluded from some of the analyses. Of the 54 responding laboratories, 44 (81%) indicated that their institution measured physician productivity. Thirty-seven of the pediatric echocardiography laboratories reported the use of relative value unit (RVU) data, and 19 programs used these data to determine physician financial packages.
| Variable | Median (range) | Mean ± SD |
|---|---|---|
| Laboratory volume (studies/year) | ||
| Total | 9,900 (3,100–28,500) | 10,755 ± 5,097 |
| TTE | 7,605 (2,800–25,000) | 8,956 ± 4,614 |
| TEE | 317 (76–1,366) | 352 ± 201 |
| Fetal echocardiography | 507 (60–2,576) | 744 ± 574 |
| Outreach/telemedicine | 714 (0–6,500) | 1,264 ± 1,436 |
| Number of physicians (calculated FTE) ∗ | 2.7 (1.2–6.0) | 2.7 ± 1.0 |
| Number of sonographers (calculated FTE) † | 7.4 (1.4–21.4) | 7.9 ± 3.7 |
| Number of ultrasound systems | 8 (2–20) | 8.7 ± 3.9 |
| Usual number of weekend echocardiographic studies | 8 (2–38) | 9.4 ± 6.1 |
∗ Physician FTE was calculated on the basis of nonoverlapping coverage of TTE, TEE, and fetal echocardiography (see “Methods”).
† Sonographer FTE was calculated on the basis of the number of full-time and part-time sonographers (see “Methods”).
Laboratory Organization
In a majority of the laboratories (37 of 54 [69%]), physicians covered a combination of TTE, TEE, and fetal echocardiography. At 17 centers (31%), separate physicians covered each service on a daily basis. At a large majority of the centers (49 [91%]), physicians were assigned to the echocardiography laboratory for half-day or full-day sessions. Physicians had other clinical responsibilities in addition to echocardiography coverage in 19 of the programs (35%). As expected, laboratory protocols varied. Specialized echocardiographic parameters (e.g., strain assessment or three-dimensional imaging) were performed as part of the routine echocardiography protocol in 34 of the laboratories (63%), which reflects the academic focus of most of the survey respondents. Physician-assisted echocardiography sedation services were available in 41 of the programs (76%). Additional laboratory personnel included a fourth-year imaging or echocardiography fellow in 25 of the laboratories (45%). Dedicated echocardiography research personnel (sonographers or research assistants) or a core research laboratory were present in 22 of the programs (41%).
Echocardiography physicians officially read weekend studies on the weekend in 29 of the programs (54%), on the next business day in 16 (30%), and “other” (usually read on the weekend when an echocardiography physician was on call) in nine (17%). Sonographers assisted with TEE or fetal echocardiography in 46 (85%) of the programs.
Staff Productivity
Without adjusting for case complexity, time requirement for TEE and fetal echocardiography, level of expertise, and availability of sonographer assistance, the average number of studies read per physician FTE per day was 15.0 ± 4.5 ( Table 2 ). Not adjusting for studies performed by attending physicians or fellows, the average number of studies per sonographer FTE per year was 1,297 ± 326. The distributions of studies per physician FTE per day ( Figure 1 ) and studies per sonographer FTE per year ( Figure 2 ) between sites emphasize the variability in practice patterns across the different laboratories surveyed. These two measures were selected as outcomes for further analysis of laboratory variation, because they were deemed the more representative for comparisons between laboratories.
| Variable | Median (range) | Mean ± SD |
|---|---|---|
| Physician productivity | ||
| Estimated daily FTE | 2.7 (1.2–6.0) | 2.7 ± 1.0 |
| Studies/FTE/year | 3,457 (1,550–6,778) | 3,746 ± 1,116 |
| Studies/FTE/day | 13.8 (6.2–27.1) | 15.0 ± 4.5 |
| Sonographer productivity | ||
| Studies/FTE/year | 1,279 (717–2,475) | 1,297 ± 326 |
To understand the factors that influenced the variability of physician productivity (defined as studies per physician FTE per day), bivariate and multivariate statistical analyses were undertaken. The continuous variables assessed were laboratory volumes (total studies, TTE, fetal echocardiography, TEE, outreach or telemedicine, and weekend studies), surgical volume, physician number, calculated daily physician FTE, calculated sonographer annual FTE, and number of ultrasound systems. The categorical variables assessed were daily (combined/separate services) coverage, echocardiography only or with other clinical responsibilities, weekend physician coverage, sonographer assistance with TEE or fetal echocardiography, specialized testing, sedation, fourth-year fellow, and research personnel. Two additional categorical variables were added to see if they influenced the models: (1) institutional tracking of productivity (yes or no) and (2) use of such data for physician financial package (compensation or incentive on the basis of quantitative clinical productivity data).
For studies per physician FTE per day, the variables listed in Table 3 were significant on Pearson’s correlation bivariate analysis. Using these variables in multivariate models, the only variable that influenced echocardiographic volume per physician was total studies in the laboratory during the survey year ( P = .001), which accounted for 19% of physician productivity. This result indicated that physicians were generally more productive in higher volume laboratories. The number of transesophageal and fetal echocardiographic studies did not affect total laboratory volume. Notable factors found not to influence physician productivity included, but were not limited to, surgical volume, TEE or fetal echocardiography volume, research protocols, the presence of fourth-year fellows, physician-assisted sedation programs, and sonographer-assisted TEE or fetal echocardiography. The tracking of productivity data or their use in determining financial compensation were also found not to correlate with calculated physician productivity.
| Variable | Pearson’s correlation coefficient | Significance with physician studies per FTE per day (two tailed P value) |
|---|---|---|
| Sonographer studies per FTE per year ( n = 52) | 0.325 | .019 |
| Total studies in laboratory during survey year ( n = 52) | 0.458 | .001 |
| TTE ( n = 52) | 0.427 | .002 |
| Number of ultrasound systems in laboratory ( n = 52) | 0.319 | .021 |
With similar bivariate analyses, four variables were noted to be positively associated with studies per sonographer FTE per year: outreach or telemedicine, calculated sonographer annual FTE (see “Methods”), total studies, and weekend physician coverage. The best multivariate model showed that 68% of sonographer productivity was accounted for by calculated sonographer annual FTE, total studies, and weekend coverage. The number of studies per sonographer per year was correlated positively with total laboratory volume but negatively with the number of sonographers and weekend coverage by physicians. As might have been expected, sonographer productivity was greatest in higher volume laboratories and in laboratories with fewer sonographers. Weekend physician coverage may have inflated the number of studies credited to sonographers, as the survey did not ask if sonographers were also assigned to the weekends.
Results
Of the 74 academic pediatric echocardiography laboratories contacted, 54 (73%) completed the survey. The responding centers all reported 12 months of data, with 51 reporting on the 2010 calendar year and three using other fiscal year dates (one each starting July 2009, September 2009, and April 2010).
The characteristics of the 54 participating echocardiography laboratories are provided in Table 1 . As expected, most of the laboratories were large academic laboratories affiliated with training programs and moderate to very large surgical programs. The annual numbers of heart surgery cases at the responding institutions were <150 at four, 150 to 249 at 14, 250 to 349 at 12, and ≥350 at 24. One program operated in a group physician model without sonographers and thus was excluded from some of the analyses. Of the 54 responding laboratories, 44 (81%) indicated that their institution measured physician productivity. Thirty-seven of the pediatric echocardiography laboratories reported the use of relative value unit (RVU) data, and 19 programs used these data to determine physician financial packages.
