Chapter 33 — Exercises

How to use these. Section E is arithmetic and should be drilled until weight × base rate is automatic; every figure in it is a constructed teaching figure. Sections B and G are the reasoning sections — principal diagnosis and present on admission — and they are where inpatient coders are actually made. Items marked † have worked solutions in the answers appendix. No answers appear in this file.

All accounts, weights, rates, and lengths of stay in these exercises are constructed teaching figures. Verify every real-world value in the current year's IPPS final rule and code sets.

Section A — The stay, not the service (items 1–4)

A.1 In one sentence each: what did Medicare pay hospitals for before October 1, 1983, and what has it paid them for since?

A.2 An inpatient UB-04 carries forty charge lines totaling a five-figure amount. State precisely what role those charges play in the payment — the two roles they still have, and the one they no longer have.

A.3 One admission at Ridgeview generates how many claims, at minimum, and under which payment logics? Name the chapter that governs each.

A.4 Name three kinds of facility excluded from IPPS, and state why a coder moving to one of them should not assume this chapter's arithmetic transfers.

Section B — Principal diagnosis, inpatient rules (items 5–9)

B.5 † A patient is admitted from the ED with severe abdominal pain. Workup over two days establishes acute cholecystitis; surgery is performed on day 2. What is the principal diagnosis — the pain or the cholecystitis — and which three words of the UHDDS definition decide it?

B.6 A patient is admitted for a scheduled knee replacement. In pre-op holding she develops chest pain; the surgery is canceled and the stay becomes a two-day cardiac workup that rules out infarction. Which rule from §33.2 is in play, and what governs the selection?

B.7 † The discharge summary documents both an acute COPD exacerbation and acute diastolic heart failure, both present on admission, both treated aggressively, and states the patient was "admitted for management of both." What discretion does the coder hold, what bounds it, and what is riding on the choice in DRG terms?

B.8 A discharge summary's final diagnosis reads "probable bacterial pneumonia." (a) How is this coded on the inpatient claim, and under which Guidelines rule from Chapter 9 §9.5? (b) The same phrase appears in an office note — what changes?

B.9 Explain why a condition first documented on day 3 of a stay can never be the principal diagnosis, no matter how severe — and name the indicator on the claim that tells the payer when the condition arose.

Section C — CC and MCC (items 10–13)

C.10 Define CC and MCC, and state which organization maintains the designations, where they are published, and how often they change.

C.11 † A record carries one MCC and four CCs among its secondary diagnoses. A colleague argues the four CCs should be dropped "since they don't change the DRG." Give the two-part response: what the CCs do to this claim's payment, and the three reasons they still belong on the claim.

C.12 Why can the principal diagnosis never serve as its own CC or MCC? Answer from the structure of the severity split.

C.13 On Account 22-8891, name the MCC, its POA indicator, and the DRG family tier it produces — and state what tier the record would support if that one code were absent and at least one documented CC remained.

Section D — How a DRG is assigned (items 14–17)

D.14 Put the grouper's steps in order: severity split · pre-MDC check · MDC assignment · surgical partition. State what input drives each step.

D.15 † "The patient had surgery, so this is a surgical DRG." Give the precise correction, and name the code set and designation that actually decide the partition.

D.16 A COPD-exacerbation admission (J44.1 principal, J96.01 secondary, POA = Y) is grouped by software still running last fiscal year's grouper version. Name two distinct ways the result could be wrong even though every code is correct.

D.17 Walk §33.2's pneumonia patient (J18.9 principal, J44.9 secondary, no CC/MCC designation on the secondaries) through all four grouper steps to a named DRG from the family this chapter uses.

Section E — The payment arithmetic (items 18–22)

Use Ridgeview's constructed base rate of \$6,200.00 throughout.

E.18 Compute the payment for a DRG with relative weight 1.0000. What is the base rate, in one sentence?

E.19 † Compute the payments for weights 1.1015, 0.8003, and 0.6555, then compute all three pairwise differences. Label which difference this book calls "the MCC's value" and which "the CC's value," and verify the two smaller differences sum to the largest.

E.20 A surgical DRG carries a constructed weight of 2.4500. Compute the payment, and state why neither a two-day early discharge nor a \$4,000 increase in billed charges changes it.

E.21 † Ridgeview's constructed base rate is built as a labor share of \$4,216.00 at wage index 1.0000 plus a non-labor share of \$1,984.00. Recompute the base rate for an otherwise identical hospital in a market with wage index 1.1000, and then price DRG 190 (weight 1.1015) there. Show every step and check your footing.

E.22 List four payment adjustments that IPPS layers on top of weight × base rate, and state in one sentence why this book names them without computing them.

Section F — Case mix index (items 23–25)

F.23 † A five-discharge period [constructed] groups to weights 1.1015, 1.1015, 0.8003, 0.6555, and 2.4500. Compute the CMI to four decimal places and the average payment per case at Ridgeview's base rate. Check the average payment against the payments computed individually.

F.24 The chief financial officer reports "CMI rose; our patients are sicker." Give the competing explanation the number cannot rule out, and describe the split a coding manager should present before anyone takes credit.

F.25 Explain why "raise the CMI" is a dangerous instruction to give a coding department, and restate it as the legitimate instruction it is usually groping toward.

Section G — POA and HAC reasoning (items 26–29)

G.26 Give the five POA values and the payment treatment of each. Which value "penalizes the record," which "respects the clinician," and why is that asymmetry the policy's design in miniature?

G.27 † For each condition on this constructed admission, assign the POA indicator and defend it in one sentence: (a) COPD exacerbation documented in the ED before the admission order; (b) a stage 3 sacral pressure ulcer first documented on day 2, with an admission skin assessment documenting intact skin; (c) a urinary tract infection first documented on day 3, where the physician, queried, responds that onset cannot be clinically determined; (d) a fall at home coded with W19.XXXA.

G.28 † The POA reasoning task. On a constructed record, the only MCC-tier condition is a catheter-associated urinary tract infection with POA = N; the record also carries one documented CC. (a) State what the HAC provision does to the severity split and which tier the stay lands in. (b) Using the COPD family's constructed figures as the stand-in arithmetic, state the dollar consequence of the HAC provision on this claim. (c) Now the risk manager asks whether the coder can "take another look at that POA." Write the two-sentence response a professional gives, and name the chapter that governs the query that may legitimately be sent.

G.29 Distinguish the HAC payment provision from the HAC Reduction Program in two sentences: the mechanism each uses and the unit each acts on.

Section H — Length of stay, outliers, and the transfer rule (items 30–33)

H.30 † Five constructed stays in one DRG run 2, 3, 4, 5, and 26 days. Compute the arithmetic mean and (to one decimal) the geometric mean, and explain in two sentences why the payment rules key on the geometric one.

H.31 † A constructed DRG pays \$9,300.00 in full and carries a GMLOS of 5.0 days. A patient is transferred to another acute care hospital (discharge status 02) after a 3-day stay. (a) Confirm the transfer rule applies. (b) Compute the per diem, the day-1 amount, and the total transfer payment. (c) Compute the payment for a 5-day stay ending in the same transfer, and explain the cap.

H.32 State the two directions in which a wrong discharge status corrupts the transfer rule — which direction Chapter 26's Case Study 1 ran, why no denial ever surfaced it, and the check that would have caught it for the cost of a sample and a schedule.

H.33 Describe the outlier payment's structure — where it begins, what it covers thereafter, and how the claim's charges enter the computation — and state why an outlier never makes a long stay profitable.

Section I — ICD-10-PCS at a structural level (items 34–36)

I.34 Name the seven characters of a Medical and Surgical section PCS code in order, and the two letters that never appear in any position.

I.35 † Read 0DTJ4ZZ character by character. Then state what single character would have to be reviewed first if the operative report documented that only a portion of the structure was removed, and name the two root operations whose boundary that is.

I.36 A procedure's title in the operative report says one thing; the body of the report documents a different objective. Which controls PCS root operation selection, and which earlier chapter of this book established the same discipline for CPT?

Section J — Judgment, the exam, and the Encounter (items 37–40)

J.37 The ethics dilemma. At a staff meeting, a consultant proposes a "severity capture initiative": coders will flag every admission that grouped without an MCC, and physicians will be queried only on those, with a bonus pool tied to the CMI. Identify what is defensible in the proposal, what is not, and rewrite it in one paragraph as a program a compliance officer could sign — naming the feature of a query program that distinguishes documentation integrity from DRG creep.

J.38 Certification-style. A 71-year-old is admitted through the ED for a COPD exacerbation. Documentation supports acute respiratory failure with hypoxia, present on admission. On day 2 a stage 3 sacral pressure ulcer is documented; the admission assessment documented intact skin. Which of the following is reported? (A) J96.01 principal, J44.1 secondary POA = Y · (B) J44.1 principal, J96.01 secondary POA = Y, L89.153 POA = N · (C) J44.1 principal, J96.01 secondary POA = Y, L89.153 omitted to avoid a quality flag · (D) J44.1 principal, J96.01 secondary POA = N, L89.153 POA = N. Choose, and say in one sentence each why the other three fail.

J.39 Certification-style. A hospital's payment for a stay is computed as relative weight × base rate. Which of the following, by itself, changes the payment amount? (A) length of stay rising from 3 to 5 days, within the ordinary range · (B) billed charges rising by \$2,000 · (C) a documented secondary diagnosis moving the stay from the "with CC" to the "with MCC" tier · (D) the attending physician's professional fee. Choose and defend in two sentences.

J.40 † The Encounter extension. Take this chapter's counterfactual — Account 10-4471's patient admitted with a right hip fracture, surgically repaired — and write the coder's summary for the inpatient claim: principal diagnosis (category-level is acceptable and correct where this book names no specific code), the reportable secondaries under Section III with POA indicators, the external cause codes, how the procedure is reported at a structural level, which grouper step the procedure changes, and the resulting DRG shape as this chapter's Encounter names it. Then state, in two sentences, why you cannot price it — naming the two facts a coder cannot derive from the chart.