Balance at

Beginning

Balance at

(amounts in thousands)

of Year

Additions

Deletions

End of Year

Year ended December 31, 2021

Allowance for doubtful accounts ⁽¹⁾

$

52

$

60

$

60

$

52

Allowance for sales returns ⁽²⁾

742

11,034

10,966

810

Allowance for rental asset loss ⁽³⁾

575

1,153

438

1,290

Year ended December 31, 2020

Allowance for doubtful accounts ⁽¹⁾

$

205

$

187

$

340

$

52

Allowance for sales returns ⁽²⁾

1,163

10,299

10,720

742

Allowance for rental revenue adjustments ⁽⁴⁾

411

2,579

2,594

396

Allowance for rental asset loss ⁽³⁾

395

559

379

575

Year ended December 31, 2019

Allowance for doubtful accounts ⁽¹⁾

$

693

$

612

$

1,100

$

205

Allowance for sales returns ⁽²⁾

890

17,036

16,763

1,163

Allowance for rental revenue adjustments ⁽⁴⁾

438

1,762

1,789

411

Allowance for rental asset loss ⁽³⁾

594

188

387

395

(1)

The additions to the allowance for doubtful accounts represent the estimates of bad debt expense based upon factors for which the company evaluates the collectability of accounts receivable, with actual recoveries netted into additions. Deductions are the actual write-offs of the receivables.

(2)

The additions to the allowance for sales returns represent estimates of returns based upon historical returns experience, primarily for the direct-to-consumer sales channel. Deductions are the actual returns of products.

(3)

The additions to the allowance for rental asset loss represent estimated losses of the Company’s rental assets that will potentially be unrecoverable from the patient. Deductions are the actual write-offs of the rental assets. 

(4)

The additions to the allowance for rental revenue adjustments represent estimates of revenue adjustments that will need to be recorded for billing adjustments on rental revenue, net of recoveries. Deductions are the actual adjustments and write-offs of the rental receivables for such revenue adjustments.