Indeed, we repeatedly have explained that when a claimed change in circumstances is based on events indicating the custodial parent's failure to promote a healthy relationship between a child and the noncustodial parent, those events must be “ ‘of [such] a nature or number [reflecting] a course of conduct or pattern [that] has had or threatens to have a discernable adverse effect upon the child.’ ” Buxton v. Storm, 236 Or.App. 578, 592, 238 P.3d 30 (2010), rev. den., 349 Or. 654, 249 P.3d 542 (2011) (quoting Niedert and Niedert, 28 Or.App. 309, 314, 559 P.2d 515, rev. den., 277 Or 237 (1977)) (emphasis added; bracketed material in Buxton ). Here, the trial court did not rely only on the number of days of parenting time lost to support a finding of a substantial change in circumstances; to the contrary, the court said that it would not have found the number of missed days alone to be sufficient. Rather, the court emphasized evidence indicating that the nature of mother's interference was calculated to undermine father's relationship with the children.

Where the claimed change of circumstances involves events of inadequate care and supervision, they "must be of [such] a nature or number [reflecting] a course of conduct or pattern [that] has had or threatens to have a discemable adverse effect upon the child." Niedert and Niedert, 28 Or App 309, 314, 559 P2d 515, rev den, 277 Or 237 (1977). Here, mother's pattern of actions has undermined child's ability to have a healthy relationship with father and embroiled child in the parental conflict.

In particular, mother posits, where the allegation is that a parent is not providing adequate care and supervision, "these events must be of such a nature or number that reflect a course of conduct or pattern of inadequate care which has had or threatens to have a discernable adverse effect upon the child." Collins and Collins, 183 Or App 354, 358, 51 P3d 691 (2002) (quoting Niedert and Niedert, 28 Or App 309, 314, 559 P2d 515, rev den, 277 Or 237 (1977)). Mother asserts that the record demonstrates that she neither caused the children's problems nor failed to address them as they arose — and, thus, that father failed to show the requisite change in circumstances.

"[a] change of circumstances is not established by showing that the custodial parent has made occasional mistakes since the entry of the decree, for every parent does, and a working parent in particular may have special problems of child care. Where the proof of change of circumstances is based on specific instances of purported parental misfeasance * * * these events must be of such a nature or number that reflect a course of conduct or pattern of inadequate care which has had or threatens to have a discernable adverse effect upon the child." Niedert and Niedert, 28 Or. App. 309, 314, 559 P.2d 515, rev den 277 Or. 237 (1977). Against this legal and factual background, we conclude that the trial court erred in modifying the custody provision of the dissolution judgment.

Second, the courts typically favor the one-time adjudication of a matter to prevent the undue burdening of the courts and the harassing of parties by repetitive actions. See Niedert and Niedert, 28 Or.App. 309, 313, 559 P.2d 515, rev. denied 277 Or. 237 (1977).         The main thrust of the current argument is whether the court must make a finding that a material change of circumstances has occurred under K.S.A.1999 Supp. 60-1610(a)(2) in order to modify the existing written custody agreement or whether the trial court can modify the agreement based simply on a finding that the modification is in the best interests of the children under K.S.A.1999 Supp. 60-1610(a)(3).

The change of circumstances rule serves to discourage repeated litigation of custody issues, and thereby protect the stability of children, while allowing an undesirable custody situation to be remedied. Bail, 325 Or at 392; Niedert and Niedert, 28 Or. App. 309, 313, 559 P.2d 515, rev den 277 Or. 237 (1977). The two-step analysis — a showing of changed circumstances followed by a consideration of the best interests of the child — was first announced in Kellogg v. Kellogg, 187 Or. 617, 621,213 P.2d 172 (1949):

It noted that defendant's answer came after there had been extensive discussion about admission of other acts of abuse. The court found that the prosecutor did not lure defendant into making the statement or structure the cross-examination to create an opportunity for rebuttal by otherwise inadmissible evidence. Defendant first argues that the rebuttal was improper, because he did not put his good character clearly and expressly in issue and so any evidence of bad character is not admissible. State v. Ewing, 174 Or. 487, 149 P.2d 765 (1944); State v. Davis, 54 Or. App. 133, 634 P.2d 279 (1981); State v. Henley, 27 Or. App. 607, 557 P.2d 33 (1976), rev den 277 Or. 237 (1977). The state argues that defendant's testimony was a statement of fact and not a recitation of opinion or character and may be rebutted by contradictory evidence.

In this case, no single factor rises to the level of establishing a substantial change of circumstances. See Smith and Smith, 62 Or. App. 728, 662 P.2d 772 (1983); Birge and Birge, 34 Or. App. 581, 579 P.2d 297 (1978); Niedert and Niedert, 28 Or. App. 309, 314, 559 P.2d 515, rev den 277 Or. 237 (1977). However, we conclude that, taken together, the changes are of a nature and quantity that establish the requisite change of circumstances.

We held that it was reasonable to suspect that the defendant was one of those in the car at the time of the sale and that, even if it was not, the fact that Smith used the car as the place for conducting his business of selling drugs made it reasonable to suspect that the defendant was an accomplice or frequented a place where controlled substances are used. In State v. Denny, 27 Or. App. 455, 556 P.2d 719 (1976), rev den 277 Or. 237 (1977), the police received a report that two men had robbed a store six minutes before the police stopped a car that contained the defendant and one other man; the two generally fit the description of the robbers. We held that stopping the car would normally be unjustified, but that when the police know of a crime and quick action is necessary to apprehend the offender, factors that would otherwise be marginal take on greater importance:

In this case the officer knew that a serious crime had just been committed. In State v. Denny, 27 Or. App. 455, 458, 556 P.2d 719, rev den 277 Or. 237 (1977), we said: "* * * Where, however, the police know that a crime of serious gravity has just been committed and that quick tactical reaction is necessary to apprehend the offender, then factors which would be of marginal significance in a general investigation take on heightened importance. * * *"