Patient time cost per visit and per year from travel, waiting and care hours

Adds the hours that one use of a service takes in round-trip travel, waiting and care, values them at the hourly value of time to give a time cost per visit, and multiplies by the number of uses in the period. With n counted over a year the result is the time cost per patient-year. The article's formula sums the same product over K service types; this formula is the term for one service type, and HE-CF-PTC-001 adds the terms for several types with published time estimates. It is HE-FM-COST-001 with a single resource, patient hours, whose unit cost is w.

Signature

h_v = t_trav + t_wait + t_care; c_v = w * h_v; C_T = n * c_v
Inputs
InputsDefinitionUnit
t_travRound-trip travel time for one use of the servicehours per visit
t_waitTime spent waiting for care at one use of the servicehours per visit
t_careTime spent receiving care at one use of the service, such as a consultation or time in an infusion chairhours per visit
wHourly value of patient time, for example a median wage applied to everyonecurrency per hour
nNumber of uses of the service by the patient in the periodvisits per period
Output
h_vPatient hours taken by one use of the service, with travel, waiting and care togetherhours per visit
c_vValue of the patient time taken by one use of the servicecurrency per visit
C_TMoney value of the patient's time spent on uses of the service over the periodcurrency per patient per period

Function

Patient time cost function from service use, hours per use and an hourly value of time

Maps the number of times a patient uses each type of health service, the hours each use takes in travel, waiting and care, and an hourly value of time to the money value of the patient's time in care over a period, per visit and in total. It is the resource costing sum HE-FM-COST-001 with patient hours as the resource and the hourly value as the unit cost, so the package keeps only the steps particular to patient time, which are hours built up from service counts (HE-FM-PTC-001 and HE-CF-PTC-001), the change in an incremental cost-effectiveness ratio when the time cost is added (HE-FM-PTC-002) and a value of time that depends on employment status (HE-FM-PTC-003). Productivity cost is a different cost category. The absence records HE-FN-ABSN-001, HE-FM-ABSN-002 and HE-FM-ABSN-003 value time lost from paid work as lost output, under the human capital approach or within the friction period, whereas patient time cost values the hours spent in care whether they are taken from paid work, unpaid work or leisure, and an hour taken from paid work is counted under one heading only. A value of time from another price year is moved with HE-FM-COST-002, time costs in later years are discounted with HE-FN-DISC-001, and a national total from a mean time cost per patient follows HE-FM-COI-001. Notation follows the Patient Time Cost article.

Computational function

  • Computational function for annual patient time cost from service counts with the Yabroff time estimates

    Takes a patient's yearly counts of uses of each service category, the minutes each use takes, a flag for whether round-trip travel is added and an hourly value of time, and returns the annual patient hours and the annual patient time cost, the article's sum over K service types. It follows the service-based method of Yabroff and colleagues, in which the time estimate for a category already contains the waiting time where waiting applies, round-trip travel is added to the services, and each night in hospital counts as 16 waking hours. The inputs therefore differ from the single-type variables of HE-FM-PTC-001.

    Inputs and outputs: n_k is the count of uses of category k in the year, m_k the minutes per use including any waiting, a_k is 1 when travel is added for that category and 0 otherwise, m_trav the round-trip travel minutes per use and w the hourly value of time. In the calculator line n_off, n_chemo, n_stay and n_night count office or outpatient visits, chemotherapy visits, hospital stays and hospital nights, m_off and m_chemo are the minutes per office and chemotherapy visit, m_night the minutes counted per night, h_T the annual patient hours and C_T the annual patient time cost.

    Assumption: Minutes per use are the urban (MSA) estimates in Table 1 of Yabroff and colleagues, 51.6 for an office or outpatient visit at ages 18 to 64 (the table's row for visits other than outpatient surgery, chemotherapy and radiation therapy) and 168.8 for a chemotherapy visit, which include the 1992 NHIS waiting time of 30.19 minutes, with 35.2 minutes of round-trip travel per visit and hospital time as the number of nights times 960 minutes. The paper states that travel was added to all services; one round trip per hospital stay and none per night is the reading taken here. The counts below are illustrative, not survey figures, and the value of time is the study's base-case median wage of USD 16.57 an hour in 2011.

    Worked example (Office visits, chemotherapy and one three-night stay): Illustrative counts of 4 office visits, 6 chemotherapy visits and one stay of 3 nights give 4,486.4 minutes, 74.7733 hours and an annual patient time cost of USD 1,238.99. n_off = 4; n_chemo = 6; n_stay = 1; n_night = 3; m_off = 51.6; m_chemo = 168.8; m_trav = 35.2; m_night = 960; w = 16.57; h_T = 74.7733; C_T = 1238.99

    Worked example (Hospital nights counted as 24 hours): Yabroff and colleagues tested 24 hours per hospital day in a sensitivity analysis. With 1,440 minutes per night the same counts give 98.7733 hours and USD 1,636.67. n_off = 4; n_chemo = 6; n_stay = 1; n_night = 3; m_off = 51.6; m_chemo = 168.8; m_trav = 35.2; m_night = 1440; w = 16.57; h_T = 98.7733; C_T = 1636.67

    Worked example (No service use): With no uses of any service the hours and the time cost are zero, a limiting case. n_off = 0; n_chemo = 0; n_stay = 0; n_night = 0; m_off = 51.6; m_chemo = 168.8; m_trav = 35.2; m_night = 960; w = 16.57; h_T = 0; C_T = 0

    Excel: With one row per service category, the counts in ServiceCount, the minutes per use in MinutesPerUse and the travel flags in TravelAdded, the travel minutes in TravelMinutes and the hourly value in HourlyValue, =SUMPRODUCT(ServiceCount,MinutesPerUse+TravelMinutes*TravelAdded)/60 in AnnualPatientHours gives the hours and =AnnualPatientHours*HourlyValue in AnnualPatientTimeCost the cost. A hospital stay row has 0 minutes and a travel flag of 1, and a hospital night row has 960 minutes and a flag of 0.

    R: ptc_annual <- function(n, m, a, m_trav, w) { h <- sum(n*(m+m_trav*a))/60; c(hours = h, cost = w*h) } Called as ptc_annual(c(4, 6, 1, 3), c(51.6, 168.8, 0, 960), c(1, 1, 1, 0), 35.2, 16.57) it returns 74.7733 hours and a cost of 1238.99.

    Python: def ptc_annual(n, m, a, m_trav, w): h = sum(nk*(mk+m_trav*ak) for nk, mk, ak in zip(n, m, a))/60; return h, w*h Called with the same lists it returns 74.7733 and 1238.99.

    Test (One office visit with travel): With a count of 1 in the office row and 0 elsewhere, AnnualPatientTimeCost equals 51.6 plus 35.2 minutes at USD 16.57 an hour, USD 23.97. Expected result TRUE. FALSE shows travel left out of the office row, which gives 14.25, or the minutes not divided by 60, which gives 1,438.28. Excel check =ABS(AnnualPatientTimeCost-(51.6+35.2)/60*16.57)<0.005

    Test (Hospital nights at 16 waking hours): With one stay of 3 nights and no other use, AnnualPatientTimeCost equals 35.2 plus 2,880 minutes at USD 16.57 an hour, USD 805.08. Expected result TRUE. FALSE shows the nights counted at 24 hours, which gives USD 1,202.76, or travel added to every night as well as the stay, which gives USD 834.24. Excel check =ABS(AnnualPatientTimeCost-(35.2+3*960)/60*16.57)<0.005

    Common error (Waiting added to emergency and hospital time): Yabroff and colleagues timed emergency visits, hospital stays and ambulatory surgery by the interval between arrival or admission and discharge, so waiting is already inside them. Adding the 30.19-minute wait to an urban emergency visit at ages 18 to 64, 203.3 minutes, plus 35.2 minutes of travel raises its time to 268.69 minutes against 238.5, 12.7% too much (computed here for illustration).

    Source: Yabroff KR, Guy GP Jr, Ekwueme DU, McNeel T, Rozjabek HM, Dowling E, Li C, Virgo KS. Annual patient time costs associated with medical care among cancer survivors in the United States. Medical Care. 2014;52(7):594-601. Methods, Measures subsection, which measures service frequency for the year in each category, adds travel time to all service time estimates and waiting time to office-based or hospital outpatient visits, chemotherapy and radiation therapy but not to emergency visits, hospitalisations or ambulatory surgery, and multiplies hospital days by 16 hours, an estimate of waking hours; the Analyses subsection, which applies the time estimates for each type of service, summarises patient time and applies the hourly value; Table 1, which gives the minutes per service category including wait time and 35.2 minutes of urban round-trip travel per visit; and Table 4, which reports the sensitivity analysis with 24 hours per hospital day.

    h_T = (n_off * (m_off + m_trav) + n_chemo * (m_chemo + m_trav) + n_stay * m_trav + n_night * m_night) / 60; C_T = w * h_T

Try this function

Implementations

  • Excel

    Patient time cost per visit and per year from named hour cells

    With the travel, waiting and care hours of one visit in TravelHours, WaitHours and CareHours, the hourly value in HourlyValue and the uses in the period in VisitsPerYear, the three formulas fill HoursPerVisit, TimeCostPerVisit and PatientTimeCost in turn. Times recorded in minutes are divided by 60 before entry.

    =TravelHours+WaitHours+CareHours; =HourlyValue*HoursPerVisit; =VisitsPerYear*TimeCostPerVisit

Assumptions

  • Average hours per use and one hourly value for every patient hour

    Each use of the service takes the same average travel, waiting and care time, and every hour is valued at the same w whatever the patient would otherwise have done. Yabroff and colleagues used a single median wage in their base case so that each person's time counted equally; HE-FM-PTC-003 values time by employment status instead. Round-trip travel applies to every use, and waiting is added only where the care time does not already include it, which in the same study meant office and outpatient visits, chemotherapy and radiation therapy, but not emergency visits, hospital stays or ambulatory surgery, which were timed by the interval between arrival or admission and discharge.

  • Service-based hours leave out preparation, home recovery and administrative time

    Counting only the time attached to services misses preparation at home, recovery at home and time spent on insurance matters, which Yabroff and colleagues suggest may be best estimated by survey, micro-costing or time-and-motion methods, so C_T built this way tends to understate patient time. The time of relatives who travel or wait with the patient is carer time and is costed separately.

  • One period and one price year for service counts and the value of time

    n counts uses within one stated period, a year for the time cost per patient-year, and w is in the price year of the other costs. A value from another year is moved with HE-FM-COST-002, as Yabroff and colleagues adjusted their home production value to 2011 dollars, and time costs in later years of a model are discounted with the other costs (HE-FN-DISC-001).

Worked examples

  • Infusion visits valued at GBP 15 an hour in the patient time cost example

    In the article's hypothetical comparison an infusion needs 26 hospital visits a year, each with 1.0 hour of travel, 0.5 hours of waiting and 3.0 hours in the chair. At an illustrative GBP 15 an hour each visit takes 4.5 hours worth GBP 67.50, and the 117 hours a year are worth GBP 1,755, the article's figure.

    n = 26; t_trav = 1.0; t_wait = 0.5; t_care = 3.0; w = 15; h_v = 4.5; c_v = 67.5; C_T = 1755

  • Oral treatment clinic visits valued at GBP 15 an hour

    The oral treatment in the same hypothetical comparison needs 12 clinic visits a year, each with 1.0 hour of travel, 0.5 hours of waiting and a 0.5 hour consultation. Each visit takes 2.0 hours worth GBP 30, and the 24 hours a year are worth GBP 360, as in the article.

    n = 12; t_trav = 1.0; t_wait = 0.5; t_care = 0.5; w = 15; h_v = 2.0; c_v = 30; C_T = 360

  • Infusion visits valued at GBP 7 an hour

    At the article's lower illustrative value of GBP 7 an hour the infusion's 4.5-hour visit is worth GBP 31.50 and the year's 117 hours GBP 819, the article's figure for the lower value of time.

    n = 26; t_trav = 1.0; t_wait = 0.5; t_care = 3.0; w = 7; h_v = 4.5; c_v = 31.5; C_T = 819

Common errors

  • Patient time cost counting only the time in care

    Counting only the chair or consultation time leaves out travel and waiting. For the article's infusion the hours fall to 78 against 117 and the time cost at GBP 15 an hour to GBP 1,170 against GBP 1,755, a third lower, and for the oral treatment, whose 0.5 hour consultation is a quarter of a 2.0 hour visit, the cost falls by three quarters, to GBP 90 (computed here for illustration).

  • Same hours counted as patient time and as productivity cost

    When the hours in care are taken from paid work and the analysis also values them as absence with HE-FM-ABSN-002, the same hour is counted twice. If all 117 infusion hours came out of paid work and were valued at GBP 15 under both headings, the time would add GBP 3,510 to costs in place of GBP 1,755 (computed here for illustration). The article treats this as a boundary rule, and each hour is counted under one heading only.

  • Visit times in minutes entered as hours in the patient time cost

    Entering 60, 30 and 180 minutes as hours makes each infusion visit 270 hours and the yearly time cost GBP 105,300 in place of GBP 1,755, 60 times too large (computed here for illustration). HE-VT-PTC-002 catches this.

Sources

  • Service-based patient time from travel, waiting and care estimates by Yabroff and colleagues

    Yabroff KR, Guy GP Jr, Ekwueme DU, McNeel T, Rozjabek HM, Dowling E, Li C, Virgo KS. Annual patient time costs associated with medical care among cancer survivors in the United States. Medical Care. 2014;52(7):594-601. Methods, Measures subsection, which estimates round-trip travel, waiting and care time separately for each service category, adds travel time to all service time estimates and waiting time to office-based or hospital outpatient visits, chemotherapy and radiation therapy; the Analyses subsection, which applies time estimates for each type of service, summarises patient time and applies the hourly value of patient time; and the Discussion, which states that preparation time at home, recovery time at home and time on health insurance issues were not included and may be best estimated from survey or micro-costing and time-and-motion techniques.

    View source →

  • Counts of formal medical services as the starting point for valuing patients' time

    Russell LB. Completing costs: patients' time. Medical Care. 2009;47(7 Suppl 1):S89-S93. Abstract, which states that good costing practice measures all important uses of a resource and values it consistently with other resources, and that counts of formal medical services, already measured in most studies, can serve as the starting point for valuing patients' time even when other uses of time cannot be measured.

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  • Service frequency combined with time estimates and an hourly value in cancer care

    Yabroff KR, Davis WW, Lamont EB, Fahey A, Topor M, Brown ML, Warren JL. Patient time costs associated with cancer care. Journal of the National Cancer Institute. 2007;99(1):14-23. Abstract, which states that for each service category time estimates were combined with service frequency and an hourly value of patient time, and that net time costs for the initial phase of care were applied to national numbers of new cancers, giving 2.3 billion dollars in 2005; that national step is the bottom-up scaling of HE-FM-COI-001.

    View source →

Canonical Identity

Persistent URI
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