Time to surgery as a prehabilitation window: insights from United States Medicare data

Prehabilitation has the potential to improve postoperative outcomes in older patients [1]. While the optimal duration is unknown, a 4-week programme is employed commonly [2]. To assess the feasibility of implementing a 4-week prehabilitation programme within routine surgical care, we examined the interval between surgery office visits and surgical admission (time to surgery) among Medicare beneficiaries undergoing major elective non-cardiac surgery. This retrospective cohort study utilised a 5% random sample of patients between 2017 and 2019, aged ≥ 65 y, who enrolled continuously in fee-for-service Medicare for at least 12 months and had a surgery office visit within 90 days before surgery. The study period was selected to avoid the potential influence of intra- and post-pandemic COVID-19 disruptions on elective surgical pathways. For beneficiaries with multiple surgeries, we selected the procedure with the highest surgical stress. Eligible surgeries were elective inpatient procedures with procedure codes listed in the Operation Stress Score ranging from 2 (low stress) to 5 (very high stress) [3]. Related surgery office visits were identified using Current Procedural Terminology codes 99202–99205, 99211–99215, and G2211, in combination with provider specialty codes that typically perform the respective procedures (online Supporting Information Table S1).

The following data were collected: age; combined comorbidity index [4]; sex; race/ethnicity; dual eligibility for Medicare and Medicaid; frailty (claims-based frailty index ≥ 0.25 [5, 6]); and malignant cancer diagnosis using appropriate ICD-10 codes in the primary position of the surgical inpatient claim. Time to surgery was defined as the interval between surgery office visit and inpatient admission. We examined the time to surgery by type of surgery, malignant cancer and frailty status, and tested the difference using the Mann–Whitney U test. Analyses were conducted using Python version 3.11.9. This study was approved by the Advarra/Hebrew SeniorLife Institutional Review Board and a waiver of written informed consent was obtained.

Of 421,536 surgeries performed between 2017 and 2019 (chosen to avoid the impact of the COVID-19 pandemic), we did not include outpatient procedures (n=333,781); non-elective surgeries (n=80,131); surgeries with inappropriate surgeon specialty (n=13,344); and surgeries without procedure-related surgery office visits (n=1732). This left 88,483 surgeries for analysis. The study population had a mean (SD) age of 74.4 (5.9) y; 51,085 (57.7%) female 78,287 (88.5%) White ethnicity; 5467 (6.2%) dual eligible status; 10,140 (11.5%) patients with frailty; 9366 (10.6%) patients with malignant cancer; and a mean (SD) combined comorbidity index of 2.9 (3.4). Musculoskeletal surgery was the most common (73.0%), followed by vascular (6.9%) and genitourinary surgery (5.9%) (online Supporting Information Table S2).

Median (IQR [range]) time to surgery was 25 (12–45 [1–90]) days, ranging from 16 (9–27 [1–90]) days for respiratory/thoracic surgery to 27 (13–48 [1–90]) days for musculoskeletal surgery. The proportion of beneficiaries with at least 28 days of time to surgery was 45.6%, ranging from 35.2% for vascular surgery to 49.0% for musculoskeletal surgery (Table 1). Among patients with malignant cancer, 33.0% had (median (IQR [range]) ≥ 28 days to surgery (20 (10–33 [1–90])), compared with 47.0% of non-cancer patients (26 (13–47 [1–90])). Time to surgery and the proportion with ≥ 28 days were significantly lower for musculoskeletal, neurological and abdominal/gastrointestinal surgeries, but significantly higher for genitourinary surgery. Among patients with frailty, 41.6% had (median (IQR [range]) ≥ 28 days to surgery (22 (11–41 [1–90])) compared with 46.0% of patients who were not frail (26 (13–46 [1–90]). Patients with frailty undergoing musculoskeletal surgery had a significantly shorter time to surgery and a lower proportion with ≥ 28 days, while no significant differences were observed for other surgery types (Table 1).

Table 1.

Comparison of time to surgery in relation to surgery type, cancer diagnosis and frailty status in Medicare fee-for-service beneficiaries undergoing major elective non-cardiac surgery, 2017–2019. Values are median (IQR [range]) or number (proportion).

Surgery type and population	n	Time to surgery; days	≥ 28 days to surgery
All surgery types	88,483	25 (12–45 [1–90])	40,243 (45.6%)
Malignant cancer	9366	20 (10–33 [1–90])	3092 (33.0%)
No malignant cancer	79,117	26 (13–47 [1–90])	37,151 (47.0%)
Frailtya	10,140	22 (11–41 [1–90])	4,217 (41.6%)
No frailty	78,343	26 (13–46 [1–90])	36,026 (46.0%)
Musculoskeletal	64,588	27 (13–48 [1–90])	31,657 (49.0%)
Malignant cancer	56	10.5 (5–24.5 [1–53])	12 (21.4%)
No malignant cancer	64,532	27 (13–48 [1–90])	31645 (49.0%)
Frailty	6573	25 (12–44 [1–90])	2943 (44.8%)
No frailty	58,015	27 (13–48 [1–90])	28,714 (49.5%)
Vascular	6094	20 (10–36 [1–90])	2145 (35.2%)
Malignant cancer	< 11	33 (17.5–72 [1–85])	< 11 (Suppressedb)
No malignant cancer	Suppressed	20 (10–36 [1–90])	Suppressed (35.2%)
Frailty	1306	19 (10–34 [1–90])	429 (32.8%)
No frailty	4788	20 (10–36 [1–90])	1716 (35.8%)
Neurologic	3817	21 (9–37 [1–90])	1452 (38.0%)
Malignant cancer	371	8 (5–15 [1–84])	45 (12.1%)
No malignant cancer	3446	22 (11–40 [1–90])	1407 (40.8%)
Frailty	859	23 (11–40 [1–90])	353 (41.1%)
No frailty	2958	20 (9–36 [1–90])	1099 (37.2%)
Genitourinary	5228	24 (12–41 [1–90])	2284 (43.7%)
Malignant cancer	3638	26 (13–41 [1–90])	1672 (46.0%)
No malignant cancer	1590	22 (11–38 [1–90])	612 (38.5%)
Frailty	384	21 (12–37 [1–90])	149 (38.8%)
No frailty	4844	24 (12–41 [1–90])	2135 (44.1%)
Abdominal/gastrointestinal	4435	20 (11–34 [1–90])	1577 (35.6%)
Malignant cancer	2320	17.5 (9–29 [1–90])	647 (27.9%)
No malignant cancer	2115	25 (13–41 [1–90])	930 (44.0%)
Frailty	491	22 (12–38 [1–89])	182 (37.1%)
No frailty	3944	20 (11–34 [1–90])	1395 (35.4%)
Respiratory/thoracic	3588	16 (9–27 [1–90])	856 (23.9%)
Malignant cancer	2794	17 (9–27 [1–90])	664 (23.8%)
No malignant cancer	794	16 (8–27 [1–90])	192 (24.2%)
Frailty	319	16 (8–27 [1–89])	75 (23.5%)
No frailty	3269	16 (9–27 [1–90])	781 (23.9%)
Other c	733	20 (8–36 [1–90])	272 (37.1%)
Malignant cancer	180	17 (8–29 [1–86])	48 (26.7%)
No malignant cancer	553	22 (8–40 [1–90])	224 (40.5%)
Frailty	208	22 (7–44 [1–90])	86 (41.3%)
No frailty	525	20 (8–34 [1–86])	186 (35.4%)

^aFrailty was defined as claims-based frailty index ≥ 0.25.

^bCounts are suppressed per Centers for Medicare & Medicaid Services guidelines when n < 11. Additional data are suppressed to prevent back-calculation.

^cincludes integumentary and endocrine surgeries.

In total, 45.6% of Medicare fee-for-service beneficiaries had at least 4 weeks before major elective non-cardiac surgery, indicating potential for a 4-week prehabilitation programme. Although time to surgery was shorter for patients with malignant cancer in some surgery types, frailty was not consistently associated with shorter intervals, except in musculoskeletal cases. Notably, 41.6% of patients with frailty had ≥ 28 days to surgery, indicating a promising opportunity of implementing prehabilitation.

There are several limitations. Relying on Medicare claims data, we assumed the closest surgery office visits before surgical inpatient admission to be the date of surgery decision, which may underestimate the actual time available for prehabilitation. As our study only included fee-for-service Medicare beneficiaries, our findings may not be generalisable to patients enrolled in Medicare Advantage or commercial insurance, where scheduling patterns may differ. Systemic barriers such as referral practices, insurance coverage and patient adherence, may limit uptake. Future research can explore strategies to optimise scheduling practices and referral pathways to facilitate prehabilitation across surgical types, particularly for patients with frailty who may benefit most from such programmes.

Supplementary Material

ANAE_16675

Table S1. Characteristics of Medicare Fee-For-Service beneficiaries undergoing major elective non-cardiac surgery in 2017–2019

Table S2. List of provider specialty code by surgery types