Peter J. Mahowald, petitioner, Respondent, vs. Dawn L. Silbernick, Appellant.

 STATE OF MINNESOTA
 IN COURT OF APPEALS
 C6-99-307

Peter J. Mahowald, petitioner,
Respondent,

vs.

Dawn L. Silbernick,
Appellant.

 Filed July 6, 1999
 Affirmed in part, reversed in part, and remanded
 Toussaint, Chief Judge

Steele County District Court
File No. FX98166

Christopher Eric Morris, O'Neill, Traxler, Zarp, Neisen & Morris Ltd., Law Building, 222 East Main Street, P.O. Box 105, New Prague, MN 56071 (for respondent)

John Robinson Hill, Larkin, Hoffman, Daly & Lindgren, Ltd., 1500 Norwest Financial Center, 7900 Xerxes Avenue South, Bloomington, MN 55431 (for appellant)

Considered and decided by Toussaint, Chief Judge, Short, Judge, and Schultz, Judge.[*]

 U N P U B L I S H E D O P I N I O N

 TOUSSAINT, Chief Judge

On appeal from an order modifying visitation and denying her motion to replace the guardian ad litem, Dawn Silbernick argues the district court abused its discretion in (1) denying her request for an evidentiary hearing; (2) failing to make the requisite statutory findings to support a modification of the original visitation order; and (3) denying her motion to replace the guardian ad litem. Because (a) the district court significantly modified the original visitation order by eliminating the requirement that visitation be supervised and (b) Silbernick established a prima facie case that visitation placed her and the child in danger of harm, we reverse the district court's order modifying visitation and remand for an evidentiary hearing and particularized findings. Because the record does not support Silbernick's claim that the guardian ad litem failed to act in the child's best interest, we affirm the district court's denial of Silbernick's motion to replace the guardian ad litem.

 D E C I S I O N

The district court has extensive discretion in deciding questions relating to visitation. Manthei v. Manthei, 268 N.W.2d 45, 45 (Minn. 1978). The reviewing court will not disturb a visitation award unless the district court abuses its discretion by making findings unsupported by the evidence or by improperly applying the law. Hennessy v. Stelton, 302 Minn. 550, 550, 224 N.W.2d 926, 927 (1974).

 I.

Silbernick first claims the district court abused its discretion in denying her request for an evidentiary hearing before substantially modifying visitation by eliminating the supervision requirement. Substantial modifications of visitation rights require an evidentiary hearing when, by affidavits, the moving party makes a prima facie showing that visitation is likely to endanger the child's physical or emotional well being. See Minn. Stat. § 518.175, subd. 5 (1998) (providing evidentiary hearing required if custodial parent makes specific allegations that visitation places custodial parent or child in danger of harm); Lutzi v. Lutzi, 485 N.W.2d 311, 316 (Minn. App. 1992) (concluding custody modification standard governs substantial modifications of visitation rights). Insubstantial modifications or adjustments of visitation, on the other hand, do not require an evidentiary hearing and are appropriate if they serve the child's best interests. Id.

The district court originally ordered supervised visitation upon a finding that respondent Peter J. Mahowald had been convicted of criminal sexual conduct in the fourth degree, had not completed treatment, and suffered from a personality disorder that made him exploitative, highly opportunistic, and unwilling to recognize the effect of his behavior on others. On its own initiative and without an evidentiary hearing, the district court subsequently eliminated the supervision requirement on a finding that despite Silbernick's allegations, the record lacked "clear and convincing evidence" of sexual, physical, or emotional abuse.

On the record, the district court's elimination of the requirement that visitation be supervised is a substantial modification of visitation. It thus requires an evidentiary hearing if, by affidavits, the proponent of the modification is able to make a prima facie showing that visitation places the child in danger of harm. Lutzi, 485 N.W.2d at 316. Although the district court ordered the modification sua sponte, Silbernick nevertheless made a sufficient prima facie showing of endangerment. In the affidavit submitted in support of her modification motion, Silbernick specifically alleged the child exhibited crying, sleeplessness, exhaustion, diarrhea, behavioral problems, and excessive self-exploration. She also alleged deteriorating relations with the Mahowalds, threats, and intimidation. These allegations sufficiently established the prima facie showing required for an evidentiary hearing.

The district court's finding that the record lacked "clear and convincing evidence" of abuse does not support its decision to proceed without an evidentiary hearing. The determinative question is not whether the record contains clear and convincing evidence of abuse, but whether it contains prima facie evidence that visitation places the custodial parent and the child in danger of harm. Id. Similarly, the fact that neither party was a proponent of the modification does not eliminate the need for an evidentiary hearing where the modification is significant and there is prima facie evidence that visitation threatens the child's physical and emotional well being. Id. Accordingly, the district court abused its discretion in denying Silbernick's motion for an evidentiary hearing.

Because the modification ordered conflicts with the court's previous findings, the best interests of the child require an evidentiary hearing to determine whether changed circumstances justify unsupervised visitation.

 II.

Silbernick next claims the district court abused its discretion by failing to make particularized findings to support the increase in the frequency and duration of visits between Mahowald and the child.

Effective appellate review is possible only where the district court issues sufficiently specific findings to demonstrate the basis for its decision and that it considered all relevant statutory factors. Stich v. Stich, 435 N.W.2d 52, 53 (Minn. 1989); Moylan v. Moylan, 384 N.W.2d 859, 865 (Minn. 1986). Modifications that restrict visitation rights must be supported by findings that visitation is likely to endanger the child's health or development. Minn. Stat. § 518.175, subd. 5; Lutzi, 485 N.W.2d at 315. Significant modifications that do not restrict visitation rights, on the other hand, must be supported by findings that they are in the best interest of the child. Moravick v. Moravick, 461 N.W.2d 408, 409 (Minn. App. 1990) (reversing modification order reinstating father's visitation rights for lack of particularized findings and remanding for evidentiary hearing to determine child's best interests); Chapman v. Chapman, 352 N.W.2d 437, 441 (Minn. App. 1984) (holding expansion of father's holiday visitation and elimination of requirement that he take children to Mass are significant modifications and must be supported by findings that they are in children's best interests).

The district court significantly modified Mahowald's visitation rights by adding visitation on alternate holidays, on four consecutive weeks during the summer, and overnight every other weekend. The district court was therefore required to make particularized findings that the modifications were in the child's best interests. No particularized finds were made. Without those findings, it is difficult to discern the basis for its decision and determine whether it considered all relevant factors. Because the reviewing court's independent review of the record is inappropriate where, as here, it is unclear whether the district court considered the required statutory factors, Moylan v. Moylan, 384 N.W.2d at 865, effective appellate review is impossible. We therefore remand for the requisite findings.

 III.

Finally, Silbernick argues the district court abused its discretion in denying her motion to replace the guardian ad litem. A guardian ad litem's duty is to protect the child's best interests. Weiler v. Lutz, 501 N.W.2d 667, 672 (Minn. App. 1993), aff'd sub nom on other grounds Valentine v. Lutz, 512 N.W.2d 868 (Minn. 1994). The district court has broad discretion in determining the child's best interests. Weiler, 50 N.W.2d at 672. By extension, it also has broad discretion in determining whether the child's best interests mandate replacement of the guardian ad litem. Id.

Silbernick contends the guardian ad litem must be replaced because she belittles her, appears to have no time to investigate visitation issues, and easily succumbs to pressure from Mahowald and his family. The record does not support Silbernick's contentions. Nor does it contain evidence that the guardian ad litem otherwise failed to act in the child's best interests. On the contrary, the guardian ad litem's letters and proposed visitation schedules show her primary goal was to ensure the child would maintain a safe and satisfying relation with her father. Moreover, the court adequately addressed Silbernick's concerns regarding the guardian ad litem's role by ordering her not to act as a mediator or a visitation expeditor. Thus, the court was well within its discretion in denying Silbernick's motion to replace the guardian ad litem.

  Affirmed in part, reversed in part and remanded.

[*] Retired judge of the district court, serving as judge of the Minnesota Court of Appeals by appointment pursuant to Minn. Const. art. VI, § 10.