Home Health & Hospice Week

Interactions between codes, OASIS items will shake things up in the new year.

Simple diagnosis coding mistakes could cost you big bucks under the revised prospective payment system, so you'd better make sure your coding is up to snuff.

PPS' clinical domain--now called the clinical dimension--will undergo these coding changes when the PPS refinements hit Jan. 1, noted consultant Mark Sharp in a recent Eli audioconference on the changes:

• A greatly expanded list of case mix diagnosis codes. The Centers for Medicare & Medicaid Services will increase the current four case mix diagnosis groups (neurological, orthopedic, diabetes and burns and trauma) to 22 new groups with hundreds of codes.

Change from proposed rule: Those include two categories on ostomies tacked on since the proposed rule. CMS "added appropriate variables in both the case mix model and the [nonroutine supplies] model to capture patients with resource needs or supplies cost needs due to tracheostomy and urostomy/cystostomy," the agency says in the final rule issued Aug. 22. Three V codes make up those categories--V55.0 (Tracheostomy), V55.5 (Cystostomy) and V55.6 (Other artificial opening of urinary tract).

• An expanded OASIS form with space for six diagnosis codes. PPS will count the diagnosis codes in the primary and secondary positions toward case mix. And  when a M0 item requires an accompanying diagnosis code to add points, PPS will count the diagnosis codes in all six positions.

• M0246 will replace M0245 and allow for a replacement code when a non-paying V code bumps a case mix code out of the primary or secondary positions.

The new OASIS item is "looking at all diagnoses" listed, explained Sharp, with BKD in Springfield, MO. In M0246, CMS wants you "to put a corresponding non-V code diagnosis for all diagnoses that you might have as a V code in M0230 or M0240. That is new."

• Scoring of diagnosis codes will be cumulative instead of just counting the highest-paying diagnosis group, as agencies do currently. Codes in the same case mix diagnosis group will not add together, however--only the highest-point diagnosis from the group will count.

• Scoring of diagnosis codes and OASIS items often will depend on interactions between the two.

Brace For More Complicated Case Mix Model

Under the PPS refinements rule, the case mix model is much more complex, Sharp warned in his audioconference last month. That's due to two factors:

1. The new four-equation model awards different points to the same case mix items depending on which episode and therapy threshold the patient has.

Example: A diabetes primary diagnosis can add anywhere from 1 to 12 points depending on the equation, Sharp pointed out.

2. The new model awards different points de-pending on the interaction between diagnosis codes and OASIS items and between different diagnosis codes.

Code-M0 item example: A diagnosis of dysphagia garners zero case mix points on its own. But it adds case mix points when it pairs with a M0250 answer of 3, Sharp noted.

Code-code example: A dysphagia diagnosis also adds up to six case mix points when it pairs with a code from the Neuro 3 - Stroke category.

This new complexity will make it much more challenging for clinicians to gauge the financial impact of the patient's OASIS answers.

You are no longer able to say "this patient characteristic is a major factor in payment consideration," Sharp noted. "It makes it a much more difficult payment system to predict ... as you're working your way through the core OASIS items that actually drive payment."

Get A Handle On These Non-Coding Clinical Dimension Changes

Coding isn't the only part of the clinical dimension to get a major overhaul. The dimension will drop four M0 items and add a new one on injectable meds. CMS' elimination of M0610 (Behaviors) doesn't mean CMS doesn't think they are important to reimbursement, Sharp noted.

CMS "added some diagnoses that are psych-related that account for these items that drive resource utilization," he said. "Hopefully we're covered there."

Change from proposed rule: CMS originally proposed retaining M0530 (Urinary Incontinence) in the clinical dimension. But the agency cut the M0 item in the final rule.

"In the 2005 data, a cost-increasing effect from incontinence was not observed, so it was deleted from the four-equation model," CMS explains in the rule. "An interaction in the proposed model involving incontinence and certain neurological conditions [brain disorders and paralysis (Neuro 1)] was no longer statistically significant, so this variable was removed as well."

Consider this: Agencies should also look at the clinical dimension as adding six more new items, Sharp suggested--the M0 questions from the functional dimension.

Since clinical dimension OASIS items often won't score case mix points without an accompanying item from the functional dimension, agencies should really consider those functional M0 questions as part of the clinical dimension, Sharp advised. "While they're not new to the payment system, they are new in the clinical dimension."

Note: For information on attending a PPS audioconference by Mark Sharp or other distinguished speakers.

For more details on diagnosis coding, see Eli's Home Health ICD-9 Alert at  www.elihealthcare.com/spec_health_icd-9.htm or by calling 1-800-874-9180.