Thromboembolic events are among the leading causes of maternal morbidity and mortality in the developed world.1,2 Peak incidence is in the immediate postpartum period,3 but the increased risk for their occurrence persists for up to 12 weeks postpartum.4 Previous risk factors associated with their occurrence include advanced maternal age, obesity, smoking, multiple pregnancy, thrombophilia, and after complications such as infection and blood product transfusion.5,6 The risk is also substantially increased after cesarean delivery, as demonstrated in a recent large-scale meta-analysis,7 in which venous thromboembolism (VTE) was found to be four-times more common after caesarean than vaginal delivery.
The prevention of thromboembolic events after delivery continues to concern caregivers universally, as risk factors for their occurrence only continue to increase (obesity, assisted reproduction, multiple pregnancies, and advanced maternal age). Meanwhile, the incidence of one of the significant risk factors for their occurrence—cesarean delivery—remains high, with current estimates in the United States of one in three patients undergoing a cesarean delivery.8 Therefore, we set our attention to this important and growing group of patients who could further benefit from risk reduction. Patient immobility after surgery is associated with an increased risk of VTE, whereas adequate mobility offers the benefits of enhanced bowel movement resumption and decreasing hospitalization length.9 Thus, the objective of our randomized trial was to assess the effect of a personalized feedback program using pedometers on postcesarean delivery mobility in patients at high risk for thromboembolism.
The trial was conducted at the maternity unit of the Edith Wolfson Medical Center, after approval by the institutional review board. It was registered with ClinicalTrials.gov (registration number NCT03724760), and conducted in accordance with the submitted protocol. All study participants provided written informed consent.
Included in the study were women aged 18–54 years, who underwent cesarean delivery during the study period, with one of the following risk factors for thromboembolism: preeclampsia, chronic rheumatic disease, inflammatory bowel disease, chorioamnionitis, emergent cesarean delivery, obesity, smoking (more than 10 cigarettes daily), maternal age older than 35 years, multiple pregnancy, multiparity (three or more deliveries), thrombophilia, or pronounced varicose veins. Women with medical recommendation to limit mobility after delivery (for example: postepidural headache or high risk for falling according to evaluation at admission) were not eligible to participate.
Before patient enrollment, a randomization plan was created using a web-based system (www.randomization.com), using a random permuted block algorithm. Patients were randomly assigned at a 1:1 ratio to the feedback or control groups. Sequentially numbered sealed envelopes were prepared by the maternity unit head nurse (not associated with the trial), each containing patient assignment. Patients who underwent cesarean delivery during the study period were offered participation in the trial during the first 24 hours after delivery by a trained research member, after assessment for eligibility. Those who consented were asked to wear a pedometer (HI-TEC) around their wrist starting 24 hours after delivery, for a total of 48 hours. The feedback group received personalized feedback, by one of the research staff, regarding their mobility at three set timepoints—32 hours from delivery (±4 hours), 48 hours from delivery (±4 hours), and 72 hours from delivery (±4 hours). Feedback was based on nomograms (different nomogram for each timepoint) established before the conduction of the study in a pretrial observation period of 100 patients. As part of each feedback provided, patients were presented with the appropriate feedback board (for the specific timepoint, Fig. 1) and notified regarding the number of steps they had taken, in comparison with the 25th, 50th, and 75th percentiles of steps anticipated. If below the 50th percentile, they were encouraged to achieve the next quartile by their next feedback. If above the 50th percentile—they were notified that were mobilizing properly but could improve mobility further if they wished. Patients in the control group wore the pedometer and received standard care. After 48 hours, the pedometer was removed by a member of our research team, who then inquired whether the pedometer had been removed and not worn for the full 48 hours. If so, patient data were excluded from analysis. Patients were then asked to complete a questionnaire and rate the average pain they experienced during the previous 48 hours (10-point scale, 10=maximal pain), their physical recovery (10-point scale, 10=optimal recovery), their mental recovery (10-point scale, 10=optimal recovery), and overall satisfaction with their delivery experience (10-point scale, 10=maximal satisfaction). The pedometers used did not require any maintenance from the patients during the trial and were used only to record steps. Pedometers were examined periodically by our team to detect any malfunctions, and the pedometers' measurements were periodically validated against a smart phone application.
Patient files were reviewed for demographic data. Labor and maternity charts were reviewed for complications, including fever and blood transfusions, patient pain medication consumption, breastfeeding, and total length of hospitalization. Patients were contacted by telephone two to three months after delivery and questioned regarding complications—surgical wound complications and thromboembolic events.
In accordance with our departmental protocol, after cesarean delivery, as per our routine care, patients admitted to the maternity ward are met and instructed by the nursing staff regarding the importance of ambulation after surgery. Patients may resume ambulation and gradual intake after 6 hours. Intravenous paracetamol and fluids are administered routinely for the first 24 hours after delivery, and additional analgesics are administered as requested by patient. After 24 hours, all pain medications are given on an as-needed basis per patient request. Thromboprophylaxis treatment (Enoxaparin, Clexane) is administered in selected cases, based on a patient's risk factors. Patients in the maternity ward may choose for their newborn to be with them (rooming in) or in the nursery. All rooms in the department are situated an equal distance from the nursery, approximately 50 feet.
The primary study outcome was the number of steps taken by patients. Secondary study outcomes included analgesic consumption, patient pain scores, physical recovery score, mental recovery score, and satisfaction score.
Data were analyzed with Epi Info 7.0. Continuous variables were calculated as mean±SD or median and range or interquartile range as appropriate and compared with the use of the Student t test or Mann-Whitney test. Categorical variables were calculated as number (%) and compared using the χ2 test or Fisher exact test as appropriate. All tests were two sided, and a P value of less than 0.05 was considered statistically significant.
Sample size was predetermined to detect a 25% between-group difference in the primary outcome—steps taken by patients. Based on observational data previously reported by our group and an anticipated 6,180 and 7,330±2,990 steps in the control and feedback groups, respectively,10 and based on an alpha of 0.05 and a power of 80%, 107 patients in each study group, for a total of 214 patients, were calculated to be sufficient. A randomization plan was created for 300 patients with six permuted blocks, 50 in each group, to allow for a maximal 30% lost to follow-up and incompletion rate. Enrollment for the trial was continued until at least 107 patients in each group completed their follow-up.
The study is reported in accordance to the CONSORT (Consolidated Standards of Reporting Trials) guidelines.11
From December 2018 to July 2019, 2,276 deliveries occurred at out institution, of which 428 were cesarean deliveries. One hundred eight patients in the feedback group and 107 patients in the control group completed their follow-up and were included in the analysis (Fig. 2). Three patients in the control group unintentionally received a single feedback visit, and two patients in the feedback group missed a single feedback visit. All were analyzed as allocated, according to the intention to treat principle. All feedback visits were conducted within the defined timeframe by a member of the research team.
There were no differences between the groups regarding patient age, body mass index, parity, a history of previous cesarean delivery, multiple pregnancy, comorbidities, and smoking (Table 1). Patients in both study groups delivered during their 38th week of gestation on average; 36% of cesarean deliveries in the feedback group and 38% in the control group were scheduled surgeries (Table 2). Neither intrapartum fever, blood product transfusion, nor surgical characteristics differed significantly between the groups, including operative length, estimated blood loss, presence of adhesions, and performance of tubal ligation.
A similar percentage of patients experienced postpartum complications, and the average hemoglobin decrease after delivery did not differ significantly between groups (Table 3). One hundred sixty patients were successfully contacted by telephone after delivery. Three patients in the feedback group reported hospitalization owing to suspected wound infection, one patient in the control group reported surgical repair of cesarean scar hernia, and one patient in the control group reported premature opening of surgical staples. None reported thromboembolic events.
The primary outcome (number of steps taken by patient) was significantly higher in the feedback group—5,918±3,116 vs 4,161±2,532 steps, P<.001, Table 4. Differences in the number of analgesics consumed and the average pain score were insignificant between the groups. Patients in the feedback group reported a higher physical recovery score, a higher mental recovery score, and a higher postdelivery satisfaction score (Table 4).
We conducted an analysis of patient demographics, intrapartum and postpartum course between patients who completed and did not complete their follow-up (analysis not shown). No differences were detected between the groups.
In this randomized controlled trial, we demonstrated that the use of a personalized feedback program in high-risk patients after cesarean delivery, validated by digital step counters, resulted in enhanced mobility. The increase in the number of steps taken by patients in the feedback group was not associated with higher pain scores or additional analgesic consumption but was rather associated with an improved self-reported physical and mental recovery, and higher satisfaction from the delivery experience.
Thromboembolism risk reduction is an important goal in the treatment of patients postpartum, as it continues to constitute one of the leading causes for maternal deaths globally.12 As immobility is an established factor in the pathogenesis of VTE, previous studies have addressed patient mobility postpartum. However, only limited studies have used an objective measurement with digital step counters, and were all observational.10,13,14
In considering mechanical interventions available for reducing the risk for VTE, low-quality evidence exists to support their routine use. Nevertheless, according to the new Enhanced Recovery After Surgery Society recommendations, pneumatic compression stockings should be offered to all patients after cesarean delivery,15 most likely owing to their favorable safety profile. High-quality evidence to support pharmacologic treatment in all patients after cesarean delivery is also lacking,16 and as their routine use does carry risk, different societies have adopted their own interpretations and recommendations. According to most, patient risk stratification for VTE and mobility assessment serve the basis for the identification of high-risk patients, and their treatment. The American College of Obstetricians and Gynecologists’ recommendations are for pharmacologic treatment based on patient risk factors,17 whereas the Royal College of Obstetricians and Gynecologists recommends treatment with low-molecular-weight heparin for 10 days after emergent cesarean deliveries and treatment of elective surgery patients as based on additional risk factors.18 European guidelines19 and the American College of Chest Physicians recommendations20 base the decision on treatment on initial assessment of patient mobility.
In considering whom to include in our trial, with potential benefit from an intervention to increase postcesarean delivery mobility, we identified patients with high-risk conditions for thromboembolism. In our trial, of 428 cesarean deliveries during the study period, 303 (70.8%) were found eligible for inclusion, thus considered at high risk for thromboembolism. In a previous observational study by our group, in which 100 patients were observed after cesarean delivery with digital step counters,10 we failed to note a correlation between steps taken and patient demographics, intrapartum and postpartum course. Thus, patient mobility cannot be anticipated, and it seems reasonable to aim for improving mobility in all high-risk patients. As based on nongynecologic literature,19 proper mobilization of patients after cesarean delivery potentially reduces the risk for thrombosis, but may theoretically also assist in bowel movement resumption, and decreasing hospitalization length. According to our findings, these potential benefits are not offset by an increase in patient pain or analgesic consumption after intervention, and no additional postsurgical complications, but rather with a better recovery experience as perceived by the patients.
Our trial is not without limitations. First, of 291 patients who initially consented to participate, 215 completed their follow-up—35 withdrew their consent, 28 quit participation, and 13 were excluded owing to technical considerations. This may potentially introduce selection bias. To minimize this possibility, we compared patient demographics, intrapartum and postpartum course between patients who completed and did not complete their follow-up. No differences were detected between the groups; thus, the effect is probably negligible. Second, the feedback group received three preset visits by our research team, in which feedback was provided regarding steps taken, and patients in the control group received standard care (no visits by researchers). We cannot rule out the effect of the staff visits, regardless of feedback provided. Although a control group of patients with a blinded pedometer may have been superior, patients in the control group were aware of their participation and the trial objective, thus an Hawthorne effect in this group is likely regardless, in which case the real life differences between the groups in study outcomes are probably higher than demonstrated (a nonparticipating patient with no digital step counter would probably walk less).
An additional study limitation refers to the potential for recall bias as per study design, because data regarding thromboembolic events after hospital discharge were obtained by telephone. Finally, as noted, this trial addresses an intervention aimed at improving mobility after cesarean delivery. There is no definitive cut off value for the number of steps taken which provide a clinically important difference. Furthermore, although the intervention itself was associated with positive effects with no patient risk, the true goal would be to lower thromboembolic events and maternal mortality. Although presented in the results, the current trial is significantly underpowered for such an objective. Our trial raises the need for an investigative effort to examine the large-scale effect of a change of policy which includes an intervention aimed at improving postcesarean delivery mobility, on thromboembolic events and maternal mortality. Until this is performed, we rely on the assumption that minimization of a previously established risk factor for VTE—immobility—will decrease their occurrence.
Our trial is notable for its novelty in exploring an intervention to improve postcesarean delivery mobility, using an objective means of digital step counters. We also focused on a group of clinical interest—patients evaluated as high risk for thromboembolism, according to current definitions, a group anticipated to further grow in obstetric caregiving in the future. In addition to steps taken, we evaluated additional study outcomes—patient perceived pain, physical and mental recovery, as well as overall satisfaction—which we believe are highly important to the postpartum experience.
In conclusion, this trial demonstrated a noninvasive and acceptable means of improving patient mobility after cesarean delivery in high-risk patients. This intervention was not offset by a higher rate of complications and patient pain, but rather with higher satisfaction by patients. Because the integration between technology and medicine has continued to evolve and has successfully been proven for additional patient care issues in obstetrics,21 the current trial offers a basis for interpretation, with the possible use of low-cost interventions such as smart phone applications in maternity wards and simple digital feedback. The effects of such intervention on maternal morbidity and mortality remains to be determined.
Authors' Data Sharing Statement
- Will individual participant data be available (including data dictionaries)? No.
- What data in particular will be shared? Study protocol and results.
- What other documents will be available? None.
- When will data be available (start and end dates)? Data will be available onClinicalTrials.govfrom March 2020 and for a year.
- By what access criteria will data be shared (including with whom, for what types of analyses, and by what mechanism)? Data will be open to the public through ClinicalTrials.gov.
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