Occupancy rates in both business segments grew 500 basis points on a same-quarter year-over-year basis.
Overall, our net revenue for the first quarter increased 9.3% to $1.55 billion.
Net revenue in our critical illness recovery hospital segment in the first quarter increased 18.9% to $595 million, compared to $501 million in the same quarter last year.
Patient days were up 8.4% compared to same quarter last year with over 293,000 patient days.
Occupancy in our critical illness recovery hospital segment was 75% in the first quarter, compared to 70% the same quarter last year.
Net revenue per-patient day increased 10.1% to $2,024 per-patient day in the first quarter.
Case mix index in our critical illness recovery hospitals was 1.35 in the first quarter, compared to 1.27 in the same quarter last year.
Net revenue in our rehabilitation hospital segment in the first quarter increased 14.2% to $208 million, compared to $182 million in the same quarter last year.
Patient days increased 8.3% compared to same quarter last year with over 102,000 patient days.
Occupancy in our rehabilitation hospitals was 84% in the first quarter, compared to 79% same quarter last year.
Net revenue per-patient day increased 7% to $1,853 per day in the first quarter.
Net revenue in our outpatient rehab segment for the first quarter declined 1.3% to $252 million, compared to $255 million in the same quarter last year.
Patient business were down 1.1% with 2.1 million visits in the quarter.
Our net revenue per visit was $104 in both the first quarter this year and last year.
Net revenue in our Concentra segment in the first quarter increased 6.1% to $423 million, compared to $399 million in the same quarter last year.
For the centers, patient business were down 2.8%, a 2-point [Technical difficulty] in business in the quarter.
Net revenue per visit in the centers increased slightly to $125 in the first quarter, compared to $123 in the same quarter last year.
I also want to highlight that we recorded $34 million in other operating income in the first quarter this year.
This included $16.1 million related to payments received under the CARES Act for incremental costs incurred as a result of COVID.
It also included $17.9 million related to the positive outcome of litigation with CMS. The adjusted EBITDA results for our critical illness recovery hospital segment included the recognition of this income.
Total company adjusted EBITDA for the first quarter increased 37.9% to $258.3 million, compared to $187.3 million in the same quarter last year.
Our consolidated adjusted EBITDA margin was 16.7% for the first quarter, compared to 13.2% for the same quarter last year.
Our critical illness recovery hospital segment adjusted EBITDA increased 27.9% to $113.3 million, compared to $88.6 million same quarter last year.
Adjusted EBITDA margin for the segment was 19% in the first quarter, compared to 17.7% in the same quarter last year.
Our rehab hospital segment adjusted EBITDA increased 31% to $50.5 million, compared to $38.6 million the same quarter last year.
Adjusted EBITDA margin for the rehab hospital segment was 24.3% in the first quarter, compared to 21.2% in the same quarter last year.
Our outpatient rehab adjusted EBITDA was $26.3 million, compared to $27.1 million in the same quarter last year.
Adjusted EBITDA margin for the outpatient segment was 10.4% in the first quarter, compared to 10.6% same quarter last year.
Our Concentra adjusted EBITDA increased 33.4% to $82 million, compared to $61.5 million in the same quarter last year.
Adjusted EBITDA margin was 19.4% in the first quarter, compared to 15.4% in the same quarter last year.
Earnings per common share increased 105% to $0.82 for the first quarter, compared to $0.40 for the same quarter last year.
Adjusted earnings per common share was $0.37 in the first quarter last year.
The proposed inpatient rehab rule, if adopted, would see an increase in the standard payment amount 2.47% and an increase in the high-cost outlier threshold.
The proposed long-term acute care rule, if adopted, would see an increase in the standard federal rate of 2.45% and an increase in the high-cost outlier threshold.
Additionally, the Medicare Sequester Relief bill extended temporary suspension of the 2% Medicare sequestration cut that was set to expire March 31 through the end of 2021.
For the first quarter, our operating expenses, which include our cost of services and in general and administrative expenses, were $1.33 billion or 85.9% of net revenue.
For the same quarter last year, operating expenses were $1.23 billion and 87.3% of net revenues.
Cost of services were $1.29 billion for the first quarter.
This compares to $1.2 billion in the same quarter last year.
As a percent of net revenue, cost of services were 83.6% for the first quarter.
This compares to 84.9% in the same quarter last year.
G&A expense was $35.4 million in the first quarter.
This compares to $33.8 million in the same quarter last year.
G&A as a percent of net revenue was 2.3% in the first quarter.
This compares to 2.4% of net revenue for the same quarter last year.
As Bob mentioned, total adjusted EBITDA was $258.3 million, and the adjusted EBITDA margin was 15.7% for the first quarter.
This compares to total adjusted EBITDA of $187.3 million and adjusted EBITDA margin of 13.2% in the same quarter last year.
Depreciation and amortization was $49.6 million in the first quarter.
This compares to $51.8 million in the same quarter last year.
We generated $9.9 million in equity and earnings [Technical difficulty] subsidiaries during the first quarter.
This compares to $2.6 million in the same quarter last year.
We also had a nonoperating gain of $7.2 million in the first quarter last year.
Interest expense was $34.4 million in the first quarter.
This compares to $46.1 million in the same quarter last year.
We recorded income tax expense of $45.1 million in the first quarter this year, which represents an effective tax rate of 24.7%.
This compares to the tax expense of $21.9 million and an effective rate of 23.7% in the same quarter last year.
Net income attributable to noncontrolling interest were $26.7 million in the first quarter.
This compared to $17.3 million in the same quarter last year.
Net income attributable to Select Medical Holdings was $110.5 million in the first quarter, and earnings per common share was $0.82.
At the end of the first quarter, we had $3.4 billion of debt outstanding and over $750 million of cash on the balance sheet.
Our debt balances at the end of the quarter included $2.1 billion in term loans, $1.2 billion and 6.25% senior notes and $75 million of other miscellaneous debt.
Net leverage based on our credit agreement EBITDA dropped to 3.02 times at the end of the first quarter.
This is down from 3.48 times at the end of the year and 4.76 times at the end of the first quarter last year.
Operating activities provided $239.9 million of cash flow in the first quarter.
This compares to $44.1 million in the same quarter last year.
Our day sales outstanding, or DSO, was 56 days at the end of March.
This compares to 56 days at the end of December of 2020 and 53 days at March 31 of 2020.
Investing activities used $52.6 million of cash in the first quarter.
The use of cash included $39.7 million -- $39.7 million in the purchase of property and equipment and $12.9 million in acquisition and investment activities in the first quarter.
Financing activities used $14.1 million of cash in the first quarter.
This includes $13.7 million in payments and distributions to noncontrolling interest of $400,000 in net repayments of other debts in the quarter.
Our total available liquidity at the end of the first quarter was $1.25 billion, which includes $75 million of cash and close to $500 million in revolver availability under the Select and Concentra credit agreements.
For the full-year 2021, we now expect revenue in the range of $5.7 billion to $5.9 billion, expected adjusted EBITDA to be in the range of $870 million to $900 million and expected earnings per common share to be in the range of $2.41 to $2.58.

Summary:
Overall, our net revenue for the first quarter increased 9.3% to $1.55 billion.
Earnings per common share increased 105% to $0.82 for the first quarter, compared to $0.40 for the same quarter last year.
Net income attributable to Select Medical Holdings was $110.5 million in the first quarter, and earnings per common share was $0.82.
For the full-year 2021, we now expect revenue in the range of $5.7 billion to $5.9 billion, expected adjusted EBITDA to be in the range of $870 million to $900 million and expected earnings per common share to be in the range of $2.41 to $2.58.